Biodiversity Data Journal : Species Conservation Profiles
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Species Conservation Profiles
Species conservation profiles of the endemic spiders Troglohyphantes (Araneae, Linyphiidae) from the Alps and the north-western Dinarides
expand article infoFilippo Milano, Luca Borio, Christian Komposch§, Stefano Mammola|,, Paolo Pantini#, Martina Pavlek¤,«, Marco Isaia
‡ Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
§ ÖKOTEAM – Institute for Animal Ecology and Landscape Planning, Graz, Austria
| Water Research Institute (IRSA), National Research Council (CNR), Verbania Pallanza, Italy
¶ Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
# Museo Civico di Scienze Naturali “E. Caffi.”, Bergamo, Italy
¤ Ruđer Bošković Institute, Zagreb, Croatia
« Croatian Biospeleological Society, Zagreb, Croatia
Open Access

Abstract

Background

The genus Troglohyphantes Joseph, 1882 (Araneae, Linyphiidae) includes 131 species, mainly distributed across the main European mountain ranges. The Alps and the north-western Dinarides account for 66 species, most of them showing narrow or even point-like distributions. The majority of Troglohyphantes spiders dwell in subterranean habitats including caves, mines, soil litter, rocky debris and other moist and shaded retreats. Despite being intensively studied from taxonomic, ecological and biogeographic standpoints, knowledge on the status of conservation and on the potential risk of extinction of these spiders is lagging. To date, only three species have been included in the global IUCN Red List, but their status has not been updated ever since their last assessment in 1996. The aim of this contribution is to assess the Alpine and north-western Dinaric species of the genus Troglohyphantes and to re-assess the species previously evaluated, according to the last version of the IUCN Red List Categories and Criteria.

New information

Amongst the 66 species here considered, 62 had sufficient data to allow the quantification of their Extent Of Occurrence (EOO) and Area Of Occupancy (AOO). Most of the species have a narrow distribution range, with an estimated EOO < 20,000 km2 and AOO < 2,000 km2, meeting the thresholds for the inclusion in the threatened categories. Five species have a more widespread distribution (EOO > 20,000 km2), extending across multiple countries. The quality of the data on distribution of four species was not sufficient to provide a reliable estimation of the distribution range.

A continuing decline in EOO, AOO and habitat quality was inferred for 30 species. The majority of them were subterranean specialised species, with a reduced thermal tolerance and a low dispersal ability. Accordingly, changes in subterranean microclimatic conditions due to climate change represent a major threat for these species. Land-use change and habitat alteration were identified as additional relevant threats for several species.

A considerable proportion of the species here assessed was found in protected areas and in sites of the Natura 2000 network. In addition, 14 species are formally protected by national and sub-national legislation. At present, 25 species are listed in the regional Red Lists.

Long-term monitoring programmes, management plans for both the species and their habitats, expansion of the extant protected areas and designation of new ones, should be considered as the most effective approaches to species conservation.

Keywords

climate change, IUCN, cave, Red List, subterranean species, Linyphiidae, troglobiont, karst, spiders

Introduction

The Alps and the Dinarides are known for their wide variety of habitats and they have been recognised as one of the major biodiversity hotspots in Europe (Nagy et al. 2003, Condé and Richard 2005). The combination of topographical, geomorphological and long-term climatic factors allowed the development of a very diverse and unique fauna, including spiders (Nentwig et al. 2022). Spiders (Arachnida, Araneae) are a mega-diverse group of arthropods comprising more than 50,000 currently described species (World Spider Catalog 2022). They are considered one of the most successful groups of organisms in terms of abundance, evolutionary radiation, biomass, functional roles and ecological plasticity (Turnbull 1973, Coddington and Levi 1991, Cardoso et al. 2008, Coddington et al. 2009, Foelix 2011, Jocqué et al. 2013, Nentwig 2013, Garrison et al. 2016, Mammola et al. 2017a, Dunlop et al. 2018) and they have colonised all terrestrial habitats, including subterranean ones (Mammola et al. 2018a).

Spiders have undergone a remarkable diversification in subterranean habitats (Mammola and Isaia 2017, Mammola et al. 2018a, Mammola et al. 2019b), including deep soil strata in forest, shallow voids in mountain screes and deep caves (Mammola and Isaia 2017); therein, they play an important functional role as apical predators in the subterranean food webs (Parimuchová et al. 2021).

The genus Troglohyphantes (Araneae, Linyphiidae) is predominantly distributed in the main European mountain ranges, including Pyrenees, Alps, Dinarides and Carpathians (Deeleman-Reinhold 1978, Pesarini 2001, Deltshev 2008, Isaia et al. 2011, Isaia et al. 2017, Mammola et al. 2018b). Currently, 131 species are described (Nentwig et al. 2022), most of them occurring in Europe. Their distribution is often restricted to very narrow areas, sometimes to just one or a few localities (Deeleman-Reinhold 1978, Isaia et al. 2011, Isaia et al. 2017, Mammola et al. 2018a).

Species of the genus Troglohyphantes generally show a remarkable preference for subterranean habitats (sensu Culver and Pipan 2019). They mainly occur in cold, wet and dark habitats, such as caves, bunkers, mines, but also in Shallow Subterranean Habitats (SSH, sensu Culver and Pipan 2019), including soil and leaf litter, rocky debris and other moist and shaded retreats (Fage 1919, Deeleman-Reinhold 1978, Isaia et al. 2010, Isaia et al. 2011, Isaia et al. 2017, Mammola et al. 2018a).

Troglohyphantes spiders display different levels of subterranean habitat specialisation. Species found in both caves and surface habitats are often able to withstand ecological variations, while others are almost exclusively found in caves and are characterised by behavioural, physiological and morphological adaptations to the stringent conditions of the subterranean habitat (Deeleman-Reinhold 1978, Isaia et al. 2017, Mammola et al. 2020, Mammola et al. 2022a). These adaptive traits include reduction or loss of eyes and cuticular pigmentation, thinning of the integument, heavier spination, appendage elongation, reduction in the metabolic rate leading to higher resistance to starvation, alteration of the circadian rhythm, reduction in fecundity, slower development, delayed maturation and extended longevity when compared with their surface relatives (for a review, see Mammola and Isaia 2017). Detailed descriptions and quantification of functional traits of Troglohyphantes spiders (hypogean affinity, upper thermal limits, conservation status and legal protection) are available with open access in the World Spider Trait database (Pekár et al. 2021).

As demonstrated by means of ecological niche modelling and physiological experiments (Mammola et al. 2018a, Mammola et al. 2019a), the increased specialisation to subterranean habitats seen in Troglohyphantes spiders, resulting from a long evolutionary history in a thermally stable environment, is accompanied by the concomitant narrowing of their thermal tolerance. While most species living close to the surface or in shallow subterranean environments have retained their ability to withstand temperature variations, specialised subterranean species of Troglohyphantes have lost such thermoregulatory mechanisms and are, therefore, particularly vulnerable to potential subterranean climatic variation induced by climate change (Mammola et al. 2019b).

Anthropogenic global warming is expected to significantly influence and modify the underground climate (Badino 2004, Domínguez-Villar et al. 2014), ultimately affecting subterranean biocoenosis and ecosystems (Mammola et al. 2019c, Sánchez-Fernández et al. 2021). This pressure is exacerbated by land-use change and habitat alteration, both subterranean and at the surface, which are, in general, regarded as the major threats to spider communities (Borges et al. 2016, Borges et al. 2019, Branco and Cardoso 2020, Milano et al. 2021, Mammola et al. 2022b). In addition, most of the occurrence localities of Troglohyphantes are highly isolated from each other, hindering the – already very poor – dispersal ability of these species (Cardoso et al. 2011, Mammola et al. 2015, Mammola and Isaia 2016).

Accordingly, recent analyses focusing on Western Italian Alps pointed towards a future decline in habitat suitability for specialised subterranean Troglohyphantes spiders and hypothesised potential high risk of local extinction for the most restricted endemic species (Mammola et al. 2018a). This prediction finds further confirmation in recent studies quantifying upper thermal limits of the western alpine species (Mammola et al. 2019a) showing very low ranges of thermal tolerance, especially for the most adapted species.

All in all, the existing wealth of threats facing subterranean biota (Mammola et al. 2022) and the ecological and biogeographical peculiarities of the Troglohyphantes spiders, strengthens the importance of considering these species in international and national conservation measures. Here, we aim to assess the Alpine and the north-western Dinaric species of the genus Troglohyphantes according to the International Union for Conservation of Nature (IUCN) Red List Criteria.

Methods

We compiled a comprehensive dataset with georeferenced records of the 66 species of Troglohyphantes occurring in the Alps and the north-western Dinarides, based on scientific literature, grey literature and unpublished records. We performed spatial analyses in R (R Core Team 2021), with the package 'red' – IUCN red-listing tools (Cardoso 2017), using either observed occurrences or estimated ranges. The package includes functions to calculate the Extent of Occurrence (EOO) and the Area of Occupancy (AOO), to map species ranges and to perform species distribution modelling.

In this work, we calculated EOO and AOO as follows:

- for species with low levels of subterranean adaptation (sensu Mammola et al. 2019a, hereinafter "non-specialised species"), with at least 15 records and for which we do not have full confidence about range limits, we modelled the range via species distribution modelling. Due to the lack of reliable absence data for our model species, we constructed a species distribution model using a standard presence-background algorithm (MaxEnt), with the function maxent in the 'dismo' R package (Hijmans et al. 2021). We modelled the distribution of the species using a combination of present-day climatic data and altitude above sea level (Fick and Hijmans 2017) at a spatial resolution of 30 arc-seconds (approximately 1 km at the Equator). As recommended in the literature (Peterson et al. 2011, Saupe et al. 2012, Merow et al. 2013), we calibrated species distribution models within a geographic area that we hypothesised has been accessible to the species. Considering the low dispersal potential of Troglohyphantes spiders (Mammola et al. 2018a), we approximated this area by buffering each occurrence by a diameter of 60 km. For a few species for which the density of records was low and scattered across the known distribution range (i.e. when the maximum distance between two neighbouring records exceeds 60 km), we assumed this area by buffering each occurrence record by 100 km. We performed a Principal Components Analysis on the predictor variables to generate new axes that summarised variation in fewer dimensions, thereby avoiding collinearity amongst covariates. To avoid overfitting, we retained the first four principal components. One hundred models were run for each species, using both coordinates and the associated spatial error. For each modelled distribution, we calculated EOO and AOO using specific functions in 'red' and reported their lower and upper confidence limits and the consensus values, calculated as all the cells predicted to be suitable for the species in at least 97.5%, 2.5% and 50% of the runs, respectively. These values are respectively reported as three consequent numbers in the relative sections "Extent of occurrence" and "Area of occupancy".

- for high and intermediate subterranean specialised species (sensu Mammola et al. 2019a, hereinafter "subterranean specialised") with narrow distribution ranges, we classified EOO and AOO as "observed" (in this respect see Mammola and Leroy 2017). For non-specialised species with less than 15 records, due to the unreliability of the distribution predicted by models with limited known occurrences, we based EOO and AOO on the “observed” distribution, with comments on the relative uncertainty about range limits. Particular cases are treated individually in each species profile. We used the minimum convex polygon encompassing all observations to calculate EOO and the 2 x 2 km cells known to be occupied to calculate AOO. When EOO was smaller than AOO, it was made equal as per the IUCN guidelines (IUCN Standards and Petitions Committee 2019);

We checked and validated the final maps and related values with our own expert opinion. We also produced KMLs maps using the 'red' function "kml".

We calculated the generation length of the species on the basis of the ecological information available in literature. Deeleman-Reinhold (1978) observed that subadults of Troglohyphantes species may moult up to 14 months after their collection. However, some non-specialised species passed through two moults in 5 months. Accordingly, we estimated a minimum generation length of two years for non-specialised species and four years for subterranean specialised species.

The nomenclature used in this work refers to the latest version of the World Spider Catalog (2022). All the species traits are sourced from the World Spider Trait database (Pekár et al. 2021). The toponomastics and classification of the different sectors and sub-sectors of the Alps follows the partition of the Alpine chain (SOIUSA, Marazzi 2005).

Species Conservation Profiles

Troglohyphantes achillis Isaia & Mammola, 2022

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Taxonomic notes

In Mammola et al. (2018a) and Mammola and Isaia (2016), this species was treated as T. vignai (partim). Being a subterranean specialised species, results of ecological niche modelling used to project future habitat suitability in Mammola et al. (2018a) are equally applied to this species.

Region for assessment:

  • Global
Figure(s) or Photo(s): 

Fig. 1

Figure 1.  

Troglohyphantes achillis Isaia & Mammola, 2022. Photo credit: Emanuele Biggi.

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Italy
Map of records (Google Earth): 

Suppl. material 1

Basis of EOO and AOO: Observed

Basis (narrative)

Caves in Western Alps have been extensively sampled, allowing us to define EOO and AOO of this species with reasonable confidence.

Min Elevation/Depth (m): 990
Max Elevation/Depth (m): 1414

Range description

This species is known from a few localities of the Chisone and Germanasca Valleys, in the Northern Cottian Alps, (north-western Italy) (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 57
Trend: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for other subterranean specialised Troglohyphantes species of the Western Alps, climate change is expected to affect the distribution of this species in the future. Given the reduced thermal tolerance of this organism and its low dispersal ability (Mammola et al. 2019c, Isaia et al. 2022), a reduction of its geographic distribution range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Area of occupancy

AOO (km2): 16
Trend: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for other subterranean specialised Troglohyphantes species of the Western Alps, climate change is expected to affect the distribution of this species in the future. Given the reduced thermal tolerance of this organism and its low dispersal ability (Mammola et al. 2019c, Isaia et al. 2022), a reduction of its geographic distribution range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Locations

Number of locations: 1

Justification for number of locations

The habitat where this species occurs is affected by changes in subterranean microclimatic conditions due to climate change, which is expected to impact the whole population (Mammola et al. 2018a).

Trend: Stable

Population

Number of individuals: Unknown
Trend: Decline (inferred)

Justification for trend

In view of the reduced thermal tolerance of this species (Isaia et al. 2022), alterations of the microclimatic conditions of the habitat due to climate change are expected to impact the whole population of this species.

Basis for decline: 
  • (c) a decline in area of occupancy, extent of occurrence and/or quality of habitat
Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Subpopulations

Number of subpopulations: 4
Trend: Decline (inferred)

Justification for trend

Due to the subterranean adaptation and the narrow physiological tolerance of this species, hampering dispersal through non-subterranean habitats (see Mammola et al. 2015 about high genetic structuring in this species), each locality reasonably hosts a single highly isolated subpopulation. Accordingly, we identified four subpopulations, all likely to be impacted by climate change.

Habitat

System: Terrestrial
Habitat specialist: Yes

Habitat (narrative)

This species has been collected among the floor debris and on the walls of the twilight zone, in natural caves and mine prospects located at the medium alpine montane belt, from 1,000 up to 1,400 m above sea level, characterised by mean annual temperature values ranging from 6.1 to 8.9°C (Isaia et al. 2022). See Mammola and Isaia (2016) for a characterisation of the ecological niche of the species and additional information on its preferred habitat.

Trend in extent, area or quality?: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for other species of Troglohyphantes of the Western Alps, a drastic decline in the habitat suitability of T. achillis as a consequence of climate change is expected.

Habitat importance: Major Importance
Habitats: 
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 3 mm
Generation length (yr): 4
Dependency of single sp?: No

Ecology and traits (narrative)

According to thermal tolerance tests, T. achillis shows intermediate thermal tolerance, reaching 50% mortality at temperature values 5°C above its cave temperature (Isaia et al. 2022). Females are present all year round, while males are found in small numbers in spring or early autumn and almost disappear in winter; annual sex ratio estimated on a population in a mine in the Chisone valley is 2.4:1 in favour of females (Mammola and Isaia 2016). See Mammola and Isaia (2016) and Isaia et al. (2022) for additional information on the ecological preferences of this species.

Threats

Threat type: Future
Threats:
  • 11.1. Climate change & severe weather - Habitat shifting & alteration
  • 11.2. Climate change & severe weather - Droughts
  • 11.3. Climate change & severe weather - Temperature extremes

Justification for threats

This species is potentially exposed due to its extremely narrow geographic distribution range. As seen for other species of the genus Troglohyphantes of the Western Alps (Mammola et al. 2018a), climate warming is expected to reduce the currently suitable habitat for this spider. Moreover, in view of its reduced thermal tolerance (Isaia et al. 2022), this species has a limited dispersal ability, which represents an additional concern in face of the ongoing increase of temperature.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection

Justification for conservation actions

One of the records of this species is located within the Special Area of Conservation and Special Protection Area of the Orsiera Rocciavré (SAC/SPA IT1110006).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, ecology, life cycle and possible threats throughout the range are needed.

Troglohyphantes albopictus Pesarini, 1989

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Italy
Map of records (Google Earth): 

Suppl. material 2

Basis of EOO and AOO: Observed

Basis (narrative)

This spider was collected in very few localities. Its low level of subterranean specialisation, together with the observed high altimetric range of its known distribution, possibly reflects a higher dispersal capacity when compared to subterranean specialised species. Consequently, it may be possible that the present known range of this species is underestimated.

Min Elevation/Depth (m): 22
Max Elevation/Depth (m): 1661

Range description

Troglohyphantes albopictus is restricted to the Colli Euganei, the Colli Berici and the Prealps of Veneto (north-western Italy) (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 2306
Trend: Stable

Justification for trend

This species is not strictly relegated to deep subterranean habitats, being collected both in epigean and shallow subterranean habitats. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised Troglohyphantes species (Mammola et al. 2019a), the distribution range of T. albopictus is not expected to undergo significant reduction in the near future. A deeper study on the current distribution of this species and on the potential impacts of climate change is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Area of occupancy

AOO (km2): 44
Trend: Stable

Justification for trend

This species is not strictly relegated to deep subterranean habitats, being collected both in epigean and shallow subterranean habitats. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised Troglohyphantes species (Mammola et al. 2019a), the distribution range of T. albopictus is not expected to undergo significant reduction in the near future. A deeper study on the current distribution of this species and on the potential impacts of climate change is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Locations

Number of locations: Not applicable

Justification for number of locations

No known threats to this species.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Stable

Justification for trend

There are no currently known threats to the species.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: Yes

Habitat (narrative)

The species was collected both in epigean and shallow subterranean habitats. The record from Colli Berici was collected in a damp wood, in the vicinity of a small stream. No additional information about the habitat was provided.

Trend in extent, area or quality?: Stable
Habitat importance: Major Importance
Habitats: 
  • 1.4. Forest - Temperate
  • 7.2. Caves and Subterranean Habitats (non-aquatic) - Other Subterranean Habitats

Ecology

Size: 3.9 mm
Generation length (yr): 2
Dependency of single sp?: No

Ecology and traits (narrative)

Not much is known about the ecology and life history of T. albopictus. This spider shows minor specialisation to subterranean life (Mammola et al. 2022a).

Threats

Threat type: Past
Threats:
  • 12. Other options - Other threat

Justification for threats

The existence of threats is unknown for this species.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection

Justification for conservation actions

Troglohyphantes albopictus has been recorded within several protected areas (EUAP0243 Parco Regionale dei Colli Euganei and SAC/SPA IT3260017 Colli Euganei - Monte Lozzo - Monte Ricco, SAC/SPA IT3210040 Monti Lessini - Pasubio - Piccole Dolomiti Vicentine, SAC/SPA IT3230022 Massiccio del Grappa).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, natural history, ecology and possible threats of the species would be needed.

Troglohyphantes apenninicus Isaia, Mammola & Pantini, 2017

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Italy
Map of records (Google Earth): 

Suppl. material 3

Basis of EOO and AOO: Observed

Basis (narrative)

This species was collected in two localities. Its low level of subterranean specialisation, possibly reflects a higher dispersal capacity when compared to subterranean specialised species. Given this situation, any modelling of the current habitat suitability is unreliable and the known distribution range should be taken with caution. Further research is needed on this species in order to assess its extinction risk.

Min Elevation/Depth (m): 1383
Max Elevation/Depth (m): 1401

Range description

The species is known only from two localities of the Tuscan Apennines: Abetone (Pistoiese Mountains) and Mount Sumbra (Apuan Alps) (detailed occurrences and relative references in Suppl. material 67). Remark: fig. 3 in Isaia et al. (2017):311 mistakenly reports three localities instead of two. However, localities are correctly reported in the Material (p. 312).

Extent of occurrence

EOO (km2): 8
Trend: Unknown
Causes ceased?: Unknown
Causes understood?: Unknown
Causes reversible?: Unknown

Area of occupancy

AOO (km2): 8
Trend: Unknown
Causes ceased?: Unknown
Causes understood?: Unknown
Causes reversible?: Unknown

Locations

Number of locations: Unknown

Justification for number of locations

The data available are not enough to estimate the number of locations for this species.

Trend: Unknown

Population

Number of individuals: Unknown
Trend: Unknown

Justification for trend

The population size and trend are unknown.

Causes ceased?: Unknown
Causes understood?: Unknown
Causes reversible?: Unknown

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: No

Habitat (narrative)

The species was collected in epigean localities. No additional information about the habitat was provided.

Trend in extent, area or quality?: Stable
Habitat importance: Major Importance
Habitats: 
  • 18. Unknown

Ecology

Size: 3.1 mm
Generation length (yr): 2
Dependency of single sp?: No

Ecology and traits (narrative)

Not much is known about the ecology and life history of this species. This spider shows minor specialisation to subterranean life (Mammola et al. 2022a).

Threats

Threat type: Past
Threats:
  • 12. Other options - Other threat

Justification for threats

Unknown threats.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection
  • 2.1. Land/water management - Site/area management

Justification for conservation actions

One of the known records of this species is inside protected areas (SAC IT5120009 Monte Sumbra, SPA IT5120015 Praterie primarie e secondarie delle Apuane).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, natural history, ecology and possible threats of the species would be needed.

Troglohyphantes bolognai Brignoli, 1975

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Italy
Map of records (Google Earth): 

Suppl. material 4

Basis of EOO and AOO: Observed

Basis (narrative)

There are only two records known for this spider. In light of its high subterranean specialisation and in view of the intensive sampling conducted in the area in recent years, it is hardly expected that the range could be significantly expanded by new findings.

Min Elevation/Depth (m): 728
Max Elevation/Depth (m): 810

Range description

This species is known from two caves (Sgarbu du Ventu and Tana Bertrand) in the Province of Imperia (Liguria, north-western Italy) (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 8
Trend: Decline (inferred)

Justification for trend

According to Mammola et al. (2018a), climate change will significantly affect the distribution of subterranean specialised Troglohyphantes in the future. Moreover, given the low tolerance to habitat changes of these species (see Mammola et al. 2018a) as well as their very low dispersal ability, a possible extreme reduction of the geographic range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Area of occupancy

AOO (km2): 8
Trend: Decline (inferred)

Justification for trend

According to Mammola et al. (2018a), climate change will significantly affect the distribution of subterranean specialised Troglohyphantes in the future. Moreover, given the low tolerance to habitat changes of these species (see Mammola et al. 2018a) as well as their very low dispersal ability, a possible extreme reduction of the geographic range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Locations

Number of locations: 1

Justification for number of locations

This species has been recorded in two caves, which are interpreted as a single location as they are both affected by changes in subterranean microclimatic conditions due to climate change.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Decline (inferred)

Justification for trend

In view of the reduced thermal tolerance of subterranean specialised Troglohyphantes species (Mammola et al. 2019a), alterations of the microclimatic conditions of the habitat due to climate change are expected to impact the whole population of this species.

Basis for decline: 
  • (c) a decline in area of occupancy, extent of occurrence and/or quality of habitat
Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Subpopulations

Number of subpopulations: 2
Trend: Decline (inferred)

Justification for trend

Due tothe adaptation to the subterranean medium and of the narrow physiological tolerance of this species, likely hampering dispersal through non-subterranean habitats, each cave reasonably hosts a single isolated subpopulation. Accordingly, for this species we identified two subpopulations, occurring in two different caves in the province of Imperia, Liguria. Both subpopulations are likely to be impacted by climate change.

Habitat

System: Terrestrial
Habitat specialist: Yes

Habitat (narrative)

Troglohyphantes bolognai was collected in deep hypogean habitats. No additional information on the habitat was provided.

Trend in extent, area or quality?: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for other species of the genus Troglohyphantes of the Western Alps, a drastic decline in the habitat suitability of T. bolognai as a consequence of climate change is expected.

Habitat importance: Major Importance
Habitats: 
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 2.8 mm
Generation length (yr): 4
Dependency of single sp?: No

Ecology and traits (narrative)

Specimens show pronounced eye regression and absence of pigmentation (Mammola et al. 2022a).

Threats

Threat type: Future
Threats:
  • 11.1. Climate change & severe weather - Habitat shifting & alteration
  • 11.2. Climate change & severe weather - Droughts
  • 11.3. Climate change & severe weather - Temperature extremes

Justification for threats

This species is potentially exposed due to its extremely narrow geographic distribution range, its low thermal tolerance and its low dispersal capacity. As seen for other species of the genus Troglohyphantes of the Western Alps (Mammola et al. 2018a), climate warming is expected to reduce the current suitable habitat for this spider.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection

Justification for conservation actions

Part of the distribution of T. bolognai is included in a Special Area of Conservation (SAC IT1314723 Campasso – Grotta Sgarbu Du Ventu).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, ecology, life cycle and possible threats throughout the range are needed.

Troglohyphantes bornensis Isaia & Pantini, 2008

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Italy
Map of records (Google Earth): 

Suppl. material 5

Basis of EOO and AOO: Observed

Basis (narrative)

Caves in Western Italian Alps have been extensively sampled, allowing us to define EOO and AOO of this species with reasonable confidence.

Min Elevation/Depth (m): 765
Max Elevation/Depth (m): 885

Range description

This species is restricted to four caves in the Pugnetto area, a calcschist cave complex in the province of Torino (Piemonte, north-western Italy) (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 4
Trend: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for all the subterranean specialised Troglohyphantes species of the Western Alps, climate change is expected to affect the distribution of this species in the future. Given the reduced thermal tolerance and the low dispersal ability (Mammola et al. 2019a) of this species, an extreme reduction of its geographic distribution range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Area of occupancy

AOO (km2): 4
Trend: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for all the subterranean specialised Troglohyphantes species of the Western Alps, climate change is expected to affect the distribution of this species in the future. Given the reduced thermal tolerance and the low dispersal ability (Mammola et al. 2019a) of this species, an extreme reduction of its geographic distribution range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Locations

Number of locations: 1

Justification for number of locations

The habitat where this species occurs is affected by changes in subterranean microclimatic conditions due to climate change, which is expected to impact the whole population (see Mammola et al. 2018a).

Trend: Stable

Population

Number of individuals: Unknown
Trend: Decline (inferred)

Justification for trend

In view of the reduced thermal tolerance of this species (Mammola et al. 2019a), alterations of the microclimatic conditions of the habitat due to climate change are expected to impact the whole population of this species.

Basis for decline: 
  • (c) a decline in area of occupancy, extent of occurrence and/or quality of habitat
Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Subpopulations

Number of subpopulations: 1
Trend: Stable

Justification for trend

Examining the known range of distribution of this species and taking into account habitat connectivity amongst caves in the hypogean complex of Pugnetto, it is possible to identify a single subpopulation occurring in the caves of the Pugnetto hypogean complex, in the Lanzo Valleys (Graian Alps).

Habitat

System: Terrestrial
Habitat specialist: Yes

Habitat (narrative)

Specimens have been found among stony debris in the deep cave habitat. The hypogean complex of Pugnetto consists of an isolated complex of natural calcschist caves in the Western Alps, at an elevation of approximately 800 m. All caves have openings into beech woods, with a prevalent northerly aspect to the cave opening. The entrance of the main cave, Borna Maggiore di Pugnetto, is gated to restrict visitors access.

Trend in extent, area or quality?: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for other western alpine species of the genus Troglohyphantes, a drastic decline in the habitat suitability of T. bornensis as a consequence of climate change is expected.

Habitat importance: Major Importance
Habitats: 
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 3 mm
Generation length (yr): 4
Dependency of single sp?: No

Ecology and traits (narrative)

This spider shows morphological specialisation to the subterranean habitat, with depigmentation, appendage elongation, flattening of the cephalothorax and moderate eye regression (Mammola et al. 2022a). According to thermal tests, T. bornensis shows a narrow thermal tolerance, reaching 50% mortality at temperature values of approximatively 1°C above its cave temperature (Mammola et al. 2019a).

Threats

Threat type: Future
Threats:
  • 11. Climate change & severe weather
  • 11.1. Climate change & severe weather - Habitat shifting & alteration
  • 11.2. Climate change & severe weather - Droughts
  • 11.3. Climate change & severe weather - Temperature extremes

Justification for threats

This species is potentially exposed due to its extremely narrow geographic distribution range. As seen for other Troglohyphantes species of the Western Alps (Mammola et al. 2018a), climate warming is expected to reduce the currently suitable habitat for this spider. Moreover, in view of its reduced thermal tolerance (Mammola et al. 2019a), this species has a limited dispersal ability, which represents an additional concern in face of the ongoing increase of temperature.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection
  • 2.1. Land/water management - Site/area management

Justification for conservation actions

The hypogean complex where the species occurs is protected (SAC IT1110048 Grotte del Pugnetto). Entrance to the caves is regulated by the protected area authority and is accessible by permission only. Opening to guided tours is restricted to 8 months a year, closed during winter.

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats
  • 3.1. Monitoring - Population trends
  • 3.4. Monitoring - Habitat trends

Justification for research needed

Further research on basic information such natural history, ecology and possible threats of the species are needed. Monitoring of population and habitat would be necessary to confirm future trends and to evaluate the effectiveness of regulating access to the caves.

Troglohyphantes brignolii Deeleman-Reinhold, 1978

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global
Figure(s) or Photo(s): 

Fig. 2

Figure 2.  

Troglohyphantes brignolii Deeleman-Reinhold, 1978. Photo credit: Marko Lukić.

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Croatia
Map of records (Google Earth): 

Suppl. material 6

Basis of EOO and AOO: Species Distribution Model

Basis (narrative)

Multiple sites are recorded for this non-specialised species. Therefore, it was possible to perform species distribution modelling to predict its potential range with confidence limits.

Min Elevation/Depth (m): 285
Max Elevation/Depth (m): 1086

Range description

This species has a small distribution range, restricted to Istria and Primorje-Gorski Kotar counties in north-western Croatia (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 434-1026,691
Trend: Stable

Justification for trend

This species is not strictly relegated to deep subterranean habitats, being also collected at cave entrance and occasionally in surface habitats. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. brignolii is not expected to undergo significant reduction in the near future. A deeper study on the impacts of climate change on this species is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Area of occupancy

AOO (km2): 432-824,600
Trend: Stable

Justification for trend

This species is not strictly relegated to deep subterranean habitats, being also collected at cave entrance and occasionally in surface habitats. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. brignolii is not expected to undergo significant reduction in the near future. A deeper study on the impacts of climate change on this species is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Locations

Number of locations: Not applicable

Justification for number of locations

No known threats to this species.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Stable

Justification for trend

There are no currently known threats to the species.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: No

Habitat (narrative)

This species has been collected both in deep-cave and in the vicinity of the cave entrance, sometimes in the twilight zone. In the type locality (Špilja iznad Velikog Bresta, Račja Vas), a few specimens were found just outside the entrance.

Trend in extent, area or quality?: Stable

Justification for trend

The habitats colonised by T. brignolii are as yet not threatened by direct human activities.

Habitat importance: Major Importance
Habitats: 
  • 1.4. Forest - Temperate
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 3.2 mm
Generation length (yr): 2
Dependency of single sp?: No

Ecology and traits (narrative)

Not much is known about the ecology and life history of this species. This spider shows minor specialisation to subterranean life (Mammola et al. 2022a).

Threats

Threat type: Past
Threats:
  • 12. Other options - Other threat

Justification for threats

This species is potentially exposed due to its limited geographic distribution range. However, the existence of direct threats is unknown for this species.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection

Justification for conservation actions

Most of the predicted range of T. brignolii is included in the Natura 2000 network (SCI HR2001215 Boljunsko polje, SCI HR2000601 Park prirode Učka, SPA HR1000018 Učka i Ćićarija).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, natural history, ecology and possible threats of the species would be needed.

Troglohyphantes caligatus Pesarini, 1989

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Switzerland
  • Italy
Map of records (Google Earth): 

Suppl. material 7

Basis of EOO and AOO: Observed

Basis (narrative)

This species was collected in very few localities. Its low level of subterranean specialisation, together with the high altimetric range of its known distribution, possibly reflects a higher dispersal capacity compared to subterranean specialised species. Consequently, it may be possible that the present known range of this species is underestimated.

Min Elevation/Depth (m): 580
Max Elevation/Depth (m): 1538

Range description

This species is known only from Monte San Primo (province of Como, Lombardia, northern Italy) and Monte Generoso (Ticino, southern Switzerland) (see Suppl. material 67).

Extent of occurrence

EOO (km2): 79
Trend: Stable

Justification for trend

This species is not strictly relegated to deep subterranean habitats, being collected both in epigean and hypogean habitats. In view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. caligatus is not expected to undergo significant reduction in the near future. A deeper study on the current distribution of this species and on the potential impacts of climate change is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Area of occupancy

AOO (km2): 28
Trend: Stable

Justification for trend

This species is not strictly relegated to deep subterranean habitats, being collected both in epigean and hypogean habitats. In view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. caligatus is not expected to undergo significant reduction in the near future. A deeper study on the current distribution of this species and on the potential impacts of climate change is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Locations

Number of locations: Not applicable

Justification for number of locations

No known threats to this species.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Stable

Justification for trend

There are no currently known threats to the species.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: Yes

Habitat (narrative)

There is poor information on the habitat of this species. Specimens have been collected both in hypogean and epigean habitats.

Trend in extent, area or quality?: Stable
Habitat importance: Major Importance
Habitats: 
  • 1.4. Forest - Temperate
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 2.2 mm
Generation length (yr): 2
Dependency of single sp?: No

Ecology and traits (narrative)

The ecology and life history of this species is unknown. This spider shows minor specialisation to subterranean life (Mammola et al. 2022a).

Threats

Threat type: Past
Threats:
  • 12. Other options - Other threat

Justification for threats

This species is potentially exposed due to its limited geographic distribution range. However, the existence of threats is unknown for this species.

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, ecology, life cycle and possible threats throughout the range would be needed.

Troglohyphantes caporiaccoi Brignoli, 1971

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Italy
Map of records (Google Earth): 

Suppl. material 8

Basis of EOO and AOO: Observed

Basis (narrative)

In light of its high level of subterranean specialisation, we assume that the known records of T. caporiaccoi are good proxies for defining AOO and EOO.

Min Elevation/Depth (m): 461
Max Elevation/Depth (m): 1082

Range description

This species is restricted to four caves in the Bergamasque Prealps (Lombardia, northern Italy) (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 30
Trend: Decline (inferred)

Justification for trend

According to Mammola et al. (2018a), climate change will significantly affect the distribution of subterranean specialised Troglohyphantes in the future. Moreover, given the low tolerance to habitat changes as well as the low dispersal ability, a possible extreme reduction of the geographic range of this species is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Area of occupancy

AOO (km2): 16
Trend: Decline (inferred)

Justification for trend

According to Mammola et al. (2018a), climate change will significantly affect the distribution of subterranean specialised Troglohyphantes in the future. Moreover, given the low tolerance to habitat changes as well as the low dispersal ability, a possible extreme reduction of the geographic range of this species is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Locations

Number of locations: 1

Justification for number of locations

Even though this species occurs in four caves, these are interpreted as a single location, as they are all affected by changes in subterranean microclimatic conditions due to climate change.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Decline (inferred)

Justification for trend

In view of the reduced thermal tolerance of subterranean specialised Troglohyphantes species (Mammola et al. 2019a), alterations of the microclimatic conditions of the habitat due to climate change are expected to impact the whole population of this species.

Basis for decline: 
  • (c) a decline in area of occupancy, extent of occurrence and/or quality of habitat
Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Subpopulations

Number of subpopulations: 4
Trend: Decline (inferred)

Justification for trend

Due to the adaptation to the subterranean medium and of the narrow physiological tolerance of this species, likely hampering dispersal through non-subterranean habitats, each locality can reasonably host a single isolated subpopulation. Accordingly, for this species we identified four subpopulations, corresponding to the four caves where the species has been collected. These subpopulation are likely to be impacted by climate change.

Habitat

System: Terrestrial
Habitat specialist: Yes

Habitat (narrative)

The species is strictly relegated to cave habitat.

Trend in extent, area or quality?: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for the species of the genus Troglohyphantes of the Western Alps, a drastic decline in the habitat suitability of T. caporiaccoi as a consequence of climate change is expected.

Habitat importance: Major Importance
Habitats: 
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 2 mm
Generation length (yr): 4
Dependency of single sp?: No

Ecology and traits (narrative)

This species shows a high degree of specialisation to deep subterranean habitats, with absence of pigmentation and remarkable eye regression (Mammola et al. 2022a).

Threats

Threat type: Future
Threats:
  • 11.1. Climate change & severe weather - Habitat shifting & alteration
  • 11.2. Climate change & severe weather - Droughts
  • 11.3. Climate change & severe weather - Temperature extremes

Justification for threats

This species is potentially exposed due to its extremely narrow geographic distribution range and its presumably low dispersal capacity. As seen for the Troglohyphantes species of the Western Alps (Mammola et al. 2018a), climate warming is expected to reduce the currently suitable habitat for this spider.

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, ecology, life cycle and possible threats throughout the range would be needed.

Troglohyphantes cavadinii Pesarini, 1989

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Italy
Map of records (Google Earth): 

Suppl. material 9

Basis of EOO and AOO: Unknown

Basis (narrative)

This subterranean specialised species was collected only in two localities and it has not been recorded since its description. It may be possible that the species occurs in other caves in the area. The true range is therefore unknown and not possible to model with confidence.

Min Elevation/Depth (m): 818
Max Elevation/Depth (m): 818

Range description

This species was found only in the cave of Pozzo di Cedrina and in an unspecified "cave in the nearby of Cene", both in Val Seriana (province of Bergamo, Lombardia, northern Italy) (see Suppl. material 67). It was never recorded after the original description (Pantini and Isaia 2019).

Extent of occurrence

EOO (km2): Unknown
Trend: Decline (inferred)

Justification for trend

The available data on the distribution range of this spider are not enough to estimate the species extinction risk. However, given the low tolerance to habitat changes of subterranean specialised Troglohyphantes species (see Mammola et al. 2018a) as well as their very low dispersal ability, a possible extreme reduction of the geographic range of T. cavadinii is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Area of occupancy

AOO (km2): Unknown
Trend: Decline (inferred)

Justification for trend

The available data on the distribution range of this spider are not enough to estimate the species extinction risk. However, given the low tolerance to habitat changes of subterranean specialised Troglohyphantes species (see Mammola et al. 2018a) as well as their very low dispersal ability, a possible extreme reduction of the geographic range of T. cavadinii is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Locations

Number of locations: Unknown

Justification for number of locations

The data available are not enough to estimate the number of locations for this species.

Trend: Unknown

Population

Number of individuals: Unknown
Trend: Decline (inferred)

Justification for trend

The population size is unknown. However, in view of the reduced thermal tolerance of subterranean specialised Troglohyphantes species (Mammola et al. 2019a), alterations of the microclimatic conditions of the habitat due to climate change are expected to impact the whole population of this species.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: Yes

Habitat (narrative)

The species was collected in deep cave habitat. No additional information on the habitat was provided.

Trend in extent, area or quality?: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for the western alpine species of Troglohyphantes, a drastic decline in the habitat suitability of T. cavadinii as a consequence of climate change is expected.

Habitat importance: Major Importance
Habitats: 
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 2 mm
Generation length (yr): 4
Dependency of single sp?: No

Ecology and traits (narrative)

Not much is known about the ecology of this species. This species shows a high degree of specialisation to deep subterranean habitats, with absence of pigmentation and pronounced eye regression (Mammola et al. 2022a).

Threats

Threat type: Future
Threats:
  • 11.1. Climate change & severe weather - Habitat shifting & alteration
  • 11.2. Climate change & severe weather - Droughts
  • 11.3. Climate change & severe weather - Temperature extremes

Justification for threats

As seen for the Troglohyphantes species of the Western Alps (Mammola et al. 2018a), climate warming is expected to reduce the currently suitable habitat for this spider.

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, ecology, life cycle and possible threats through out the range would be needed.

Troglohyphantes comottii Pesarini, 1989

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Italy
Map of records (Google Earth): 

Suppl. material 10

Basis of EOO and AOO: Unknown

Basis (narrative)

This subterranean specialised species was collected only in one locality, and it has never been recorded again after its description. It may be possible that the species occurs in other caves in the area. The true range is therefore unknown and not possible to model with confidence.

Min Elevation/Depth (m): 396
Max Elevation/Depth (m): 396

Range description

This species is known only from one cave (Grotta Lacù di Casai), in the province of Bergamo (Lombardia, northern Italy) (see Suppl. material 67). It is uniquely known for the type locality, as it was never recorded after the original description (Pantini and Isaia 2019).

Extent of occurrence

EOO (km2): Unknown
Trend: Decline (inferred)

Justification for trend

The available data on the distribution range of this spider are not sufficient to estimate its extinction risk. However, given the low tolerance to habitat changes of subterranean specialised Troglohyphantes species (see Mammola et al. 2019a) as well as their very low dispersal ability, a possible extreme reduction of the geographic range of T. comottii is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Area of occupancy

AOO (km2): Unknown
Trend: Decline (inferred)

Justification for trend

The available data on the distribution range of this spider are not sufficient to estimate its extinction risk. However, given the low tolerance to habitat changes of subterranean specialised Troglohyphantes species (see Mammola et al. 2019a) as well as their very low dispersal ability, a possible extreme reduction of the geographic range of T. comottii is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Locations

Number of locations: Unknown

Justification for number of locations

The data available are not enough to estimate the number of locations for this species.

Trend: Unknown

Population

Number of individuals: Unknown
Trend: Decline (inferred)

Justification for trend

The population size is unknown. However, in view of the reduced thermal tolerance of subterranean specialised Troglohyphantes species (Mammola et al. 2019a), alterations of the microclimatic conditions of the habitat due to climate change are expected to impact the whole population of this species.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: Yes

Habitat (narrative)

There is poor information on species habitat, although specimens have been collected in caves.

Trend in extent, area or quality?: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for the species of the genus Troglohyphantes of the Western Alps, a drastic decline in the habitat suitability of T. comottii as a consequence of climate change is expected.

Habitat importance: Major Importance
Habitats: 
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 2 mm
Generation length (yr): 4
Dependency of single sp?: No

Ecology and traits (narrative)

This species shows a high degree of specialisation to deep subterranean habitats, with absence of pigmentation and pronounced eye regression (Mammola et al. 2022a).

Threats

Threat type: Future
Threats:
  • 11.1. Climate change & severe weather - Habitat shifting & alteration
  • 11.2. Climate change & severe weather - Droughts
  • 11.3. Climate change & severe weather - Temperature extremes

Justification for threats

As seen for the Western alpine Troglohyphantes species (Mammola et al. 2018a), climate warming is expected to reduce the currently suitable habitat for this spider.

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, ecology, life cycle and possible threats throughout the range would be needed.

Troglohyphantes confusus Kratochvíl, 1939

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Slovenia
Map of records (Google Earth): 

Suppl. material 11

Basis of EOO and AOO: Observed

Basis (narrative)

This non-specialised spider was collected in very few localities. Its low level of subterranean specialisation possibly reflects a higher dispersal capacity when compared to subterranean specialised species. Consequently, it may be possible that the present known range of this species is underestimated.

Min Elevation/Depth (m): 453
Max Elevation/Depth (m): 650

Range description

Troglohyphantes confusus is restricted to a few localities in Inner Carniola (north-western Slovenia) (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 202
Trend: Stable

Justification for trend

This species is not strictly relegated to deep subterranean habitats, being mostly collected in epigean habitats. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. confusus is not expected to undergo significant reduction in the near future. A deeper study on the current distribution of this species and on the potential impacts of climate change is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Area of occupancy

AOO (km2): 24
Trend: Stable

Justification for trend

This species is not strictly relegated to deep subterranean habitats, being mostly collected in epigean habitats. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. confusus is not expected to undergo significant reduction in the near future. A deeper study on the current distribution of this species and on the potential impacts of climate change is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Locations

Number of locations: Not applicable

Justification for number of locations

No known threats to this species.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Stable

Justification for trend

There are no currently known threats to the species.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: No

Habitat (narrative)

This species was mainly found in beech forests, in burrows under litter. Some specimens have been collected in the anterior part of a cave, in ethylene-glycol pitfalls.

Trend in extent, area or quality?: Stable
Habitat importance: Major Importance
Habitats: 
  • 1. Forest
  • 7.2. Caves and Subterranean Habitats (non-aquatic) - Other Subterranean Habitats

Ecology

Size: 2.6 mm
Generation length (yr): 2
Dependency of single sp?: No

Ecology and traits (narrative)

Specimens show a low degree of morphological specialisation to subterranean life (Mammola et al. 2022a).

Threats

Threat type: Past
Threats:
  • 12. Other options - Other threat

Justification for threats

The existence of threats is unknown for this species.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection
  • 2.1. Land/water management - Site/area management

Justification for conservation actions

Some of the known localities of this species fall within the Special Area of Conservation of the Trnovo Forest (SAC SI3000255).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, ecology, life cycle and possible threats throughout the range would be needed.

Troglohyphantes croaticus (Chyzer, 1894)

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global
Figure(s) or Photo(s): 

Fig. 3

Figure 3.  

Troglohyphantes croaticus (Chyzer, 1894). Photo credit: Jana Bedek.

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Croatia
Map of records (Google Earth): 

Suppl. material 12

Basis of EOO and AOO: Species Distribution Model

Basis (narrative)

This species is known from multiple localities. Therefore, it was possible to perform species distribution modelling to predict its potential range with confidence limits. See Methods for details.

Min Elevation/Depth (m): 203
Max Elevation/Depth (m): 1378

Range description

This species has been found in several caves in the Primorje-Gorski Kotar, Karlovac, and Lika-Senj counties (north-western Croatia) (detailed occurrences and relative references in Suppl. material 67). The species distribution model predicts the presence of T. croaticus outside the known range, in the southern part of Slovenia.

Extent of occurrence

EOO (km2): 2664-4664,3618
Trend: Stable

Justification for trend

This species is not strictly relegated to deep subterranean habitats, being collected in the twilight zone and in the deep parts of the caves. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. croaticus is not expected to undergo significant reduction in the near future. A deeper study on the impacts of climate change on this species is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Area of occupancy

AOO (km2): 1700-3272,2536
Trend: Stable

Justification for trend

This species is not strictly relegated to deep subterranean habitats, being collected in the twilight zone and in the deep parts of the caves. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. croaticus is not expected to undergo significant reduction in the near future. A deeper study on the impacts of climate change on this species is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Locations

Number of locations: Not applicable

Justification for number of locations

No known threats to this species.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Stable

Justification for trend

There are no currently known threats to the species.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: No

Habitat (narrative)

Specimens have been collected both at the cave entrance and deeper in the cave, in webs amongst boulders on the cave floor and on the walls. Although, to our knowledge, for the majority of localities no threats are detectable, the species has apparently disappeared from the type locality, Bukovac Cave. It seems likely that extensive archaeological and paleontological excavations carried out in this cave have altered significantly the habitat of this species. Moreover, Cave Vrelo is a touristic cave with more than 10,000 visitors per year, in which concerts, exhibitions and filming of movies are organised, with the possible accumulation of litter that may alter the local microhabitat.

Trend in extent, area or quality?: Stable

Justification for trend

Most of the caves inhabited by T. croaticus are as yet not threatened by direct human activities. However two localities seems to be disturbed by past and ongoing human activities, i.e. excavations and touristic use.

Habitat importance: Major Importance
Habitats: 
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 2.8 mm
Generation length (yr): 2
Dependency of single sp?: No

Ecology and traits (narrative)

Specimens collected in the eastern part of the distribution (in the regions of Kordun and Ogulinsko-plaščansko područje) are depigmented and microphthalm. Specimens from the western part of the distribution (Gorski kotar region) appear to be rather variable, from eyeless depigmented individuals to fully pigmented ones (even with a pattern on the opisthosoma) and normal eyes. According to the latest population genetic study of the species (Pavlek et al. in press), there is a clear separation on eastern and western subpopulations, with no evidence of gene flow between them.

Threats

Threat type: Past
Threats:
  • 12. Other options - Other threat

Justification for threats

This species is potentially exposed due to its limited geographic distribution range. However, the existence of direct threats is unknown for this species. One of the caves where this species occurs is a show cave and visitors access it frequently.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection

Justification for conservation actions

Most of the predicted range of T. croaticus is included in the Risnjak National Park and in the Natura 2000 network (SCI HR2000447 Nacionalni park Risnjak, SCI HR2000592 Ogulinsko-plaščansko područje, SCI HR2000591 Klek, SCI HR2000643 Obruč, SCI HR2000707 Gornje Jelenje prema Platku, SCI HR2001041 Gomance, SCI HR2001340 Područje oko Kuštrovke, SCI HR2001353 Lokve-Sunger-Fužine, SCI/SPA HR5000019 Gorski kotar i sjeverna Lika). The species distribution modelling predicts that this species could also be present in the Slovenian protected site of Snežnik (SAC SI3000231 Javorniki - Snežnik, SPA SI5000002 Snežnik - Pivka).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, natural history, ecology and possible threats of the species would be needed.

Troglohyphantes cruentus Brignoli, 1971

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Slovenia
Map of records (Google Earth): 

Suppl. material 13

Basis of EOO and AOO: Unknown

Basis (narrative)

This non-specialised species was collected in a single locality. It may be possible that the species occurs in other localities in the area. The true range is therefore unknown and not possible to model with confidence.

Min Elevation/Depth (m): 500
Max Elevation/Depth (m): 500

Range description

The species is known only from one locality outside the cave of Smoganica, in the municipality of Most na Soči (Slovenian Littoral) (see Suppl. material 67).

Extent of occurrence

EOO (km2): Unknown
Trend: Unknown
Causes ceased?: Unknown
Causes understood?: Unknown
Causes reversible?: Unknown

Area of occupancy

AOO (km2): Unknown
Trend: Unknown
Causes ceased?: Unknown
Causes understood?: Unknown
Causes reversible?: Unknown

Locations

Number of locations: Unknown

Justification for number of locations

The data available are not enough to estimate the number of locations for this species.

Trend: Unknown

Population

Number of individuals: Unknown
Trend: Unknown

Justification for trend

The population size and trend are unknown.

Causes ceased?: Unknown
Causes understood?: Unknown
Causes reversible?: Unknown

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: No

Habitat (narrative)

The species was collected just outside a cave. No additional information about the habitat was provided.

Trend in extent, area or quality?: Unknown
Habitat importance: Major Importance
Habitats: 
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 2.6 mm
Generation length (yr): 2
Dependency of single sp?: No

Ecology and traits (narrative)

Not much is known about the ecology of this species. The female is unknown (Nentwig et al. 2022). Specimens are depigmented (Mammola et al. 2022a).

Threats

Threat type: Past
Threats:
  • 12. Other options - Other threat

Justification for threats

Unknown threats.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection
  • 2.1. Land/water management - Site/area management

Justification for conservation actions

This species was considered as potentially threatened due to its rarity and included in the category R of the Slovenian Red List (Uradni list RS št. 82/02 in 42/10). The single known locality of this spider is currently protected (SAC SI3000209 Jama pod Smoganico) and not open to the public.

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, natural history, ecology and possible threats of the species would be needed.

Troglohyphantes delphinicus Isaia & Mammola, 2022

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Taxonomic notes

In Mammola et al. (2018a), this species was treated as T. vignai (partim). As it is a subterranean specialised species, the results of ecological niche modelling used to project future habitat suitability in Mammola et al. (2018a) are likely transferrable to this species.

Region for assessment:

  • Global
Figure(s) or Photo(s): 

Fig. 4

Figure 4.  

Troglohyphantes delphinicus Isaia & Mammola, 2022. Photo credit: Emanuele Biggi.

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Italy
Map of records (Google Earth): 

Suppl. material 14

Basis of EOO and AOO: Observed

Basis (narrative)

Caves in Western Alps have been extensively sampled, allowing to define EOO and AOO of this species with reasonable confidence.

Min Elevation/Depth (m): 1000
Max Elevation/Depth (m): 2480

Range description

The species is known in a few caves of Varaita Valley (Southern Cottian Alps) and in an isolated locality in Gesso Valley (Maritime Alps) (Piemonte, north-western Italy, detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 459
Trend: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for other spiders of the genus Troglohyphantes of the Western Alps, climate change is expected to affect the distribution of this species in the future. Given the narrow thermal tolerance and its low dispersal ability (Isaia et al. 2022), a reduction of the distribution range of this species is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Area of occupancy

AOO (km2): 24
Trend: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for other spiders of the genus Troglohyphantes of the Western Alps, climate change is expected to affect the distribution of this species in the future. Given the narrow thermal tolerance and its low dispersal ability (Isaia et al. 2022), a reduction of the distribution range of this species is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Locations

Number of locations: 1

Justification for number of locations

The habitat where this species occurs is affected by changes in subterranean microclimatic conditions due to climate change, which is expected to impact the whole population (see Mammola et al. 2018a).

Trend: Stable

Population

Number of individuals: Unknown
Trend: Decline (inferred)

Justification for trend

In view of the reduced thermal tolerance of this species (Isaia et al. 2022), alterations of the microclimatic conditions of the habitat due to climate change are expected to impact the whole population.

Basis for decline: 
  • (c) a decline in area of occupancy, extent of occurrence and/or quality of habitat
Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Subpopulations

Number of subpopulations: 4
Trend: Decline (inferred)

Justification for trend

Due to the adaptation to the subterranean habitat and of the narrow physiological tolerance of this species, hampering dispersal through non-subterranean habitats (data on gene flow from Mammola et al. 2015), each locality reasonably hosts a single isolated subpopulation. Accordingly, for this species we identified four subpopulations, all of them occurring in the province of Cuneo (Piemonte, north-western Italy). All subpopulations are likely to be impacted by climate change.

Habitat

System: Terrestrial
Habitat specialist: Yes

Habitat (narrative)

Troglohyphantes delphinicus was mainly collected in the dark zone of natural caves characterised by mean annual temperature values ranging from 0 to 8°C, at an altitude ranging from 1000 to 2480 m. In very few occasions, individuals were collected outside, in the vicinity of cave entrances in deep litter or under big stones (Isaia et al. 2022). A specimen was once collected in a pitfall trap in deep litter of a beech forest.

Trend in extent, area or quality?: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for other western alpine species of the genus Troglohyphantes, a drastic decline in the habitat suitability of T. delphinicus as a consequence of climate change is expected.

Habitat importance: Major Importance
Habitats: 
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 3 mm
Generation length (yr): 4
Dependency of single sp?: No

Ecology and traits (narrative)

According to thermal tests, this species shows a narrow thermal tolerance, reaching 50% mortality at temperature values 1°C above its cave temperature (Isaia et al. 2022). Females are present all year, while males are rarely found in spring or early autumn and almost disappear in winter (Isaia et al. 2022).

Threats

Threat type: Future
Threats:
  • 11.1. Climate change & severe weather - Habitat shifting & alteration
  • 11.2. Climate change & severe weather - Droughts
  • 11.3. Climate change & severe weather - Temperature extremes

Justification for threats

This species is potentially exposed due to its narrow geographic distribution range. As seen in Mammola et al. (2018a) for other species of the genus Troglohyphantes of the Western Alps, climate warming is expected to reduce the currently suitable habitat for this spider. Moreover, in view of its low thermal tolerance (Isaia et al. 2022), this species has a very limited dispersal ability, which represents an additional concern in face of the ongoing increase of temperature.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection

Justification for conservation actions

One of the caves where this species has been collected is within the borders of the protected area of the Maritime Alps (SAC/SPA IT1160056).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, ecology, life cycle and possible threats throughout the range would be needed.

Troglohyphantes diabolicus Deeleman-Reinhold, 1978

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Slovenia
Map of records (Google Earth): 

Suppl. material 15

Basis of EOO and AOO: Observed

Basis (narrative)

This species was collected in a few localities. Its low level of subterranean specialisation, possibly reflects a higher dispersal capacity when compared to subterranean specialised species. Consequently, it may be possible that the present known range of this species is underestimated.

Min Elevation/Depth (m): 302
Max Elevation/Depth (m): 728

Range description

This species is known from three caves of mount Tisnik in Carinthia, and from four caves in Styria (northern Slovenia) (detailed occurrences and relative references in Suppl. material 67). The species has been also collected in small mammal burrows in beech forests of the Savinian Alps (Styria, Slovenia).

Extent of occurrence

EOO (km2): 622
Trend: Unknown

Justification for trend

This species is not strictly relegated to deep subterranean environments, being collected also in shallow subterranean environments. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. diabolicus is not expected to undergo significant reduction in the near future. A deeper study on the current distribution of this species and on the potential impacts of climate change is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Area of occupancy

AOO (km2): 28
Trend: Stable

Justification for trend

This species is not strictly relegated to deep subterranean habitats, being collected also in shallow subterranean environments. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. diabolicus is not expected to undergo significant reduction in the near future. A deeper study on the current distribution of this species and on the potential impacts of climate change is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Locations

Number of locations: Not applicable

Justification for number of locations

No known threats to this species.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Stable

Justification for trend

There are no currently known threats to the species.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: No

Habitat (narrative)

Specimens have been mainly collected in subterranean environments and occasionally in shallow subterranean habitats. In the Huda Luknja Cave, a high concentration of specimens of T. diabolicus has been found among the debris of a decayed wooden bridge in the front section, not far from the entrance opening. In Knapovska jama, a deserted artificial pit, the spiders had their webs amongst wood debris and in holes in the floor left by buttress poles, 10-30 m from the entrance. Specimens have been collected also in small mammal burrows in beech forests.

Trend in extent, area or quality?: Stable
Habitat importance: Major Importance
Habitats: 
  • 1.4. Forest - Temperate
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 3.1 mm
Generation length (yr): 2
Dependency of single sp?: No

Ecology and traits (narrative)

Not much is known about the ecology and life history of this species. This spider shows minor morphological specialisation to subterranean life (Mammola et al. 2022a).

Threats

Threat type: Past
Threats:
  • 12. Other options - Other threat

Justification for threats

This species is potentially exposed due to its limited geographic distribution range. However, the existence of threats is unknown for this species.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection
  • 4. Education & awareness

Justification for conservation actions

Troglohyphantes diabolicus was considered potentially threatened and listed in the Slovenian Red List, in the category R (Uradni list RS št. 82/02 in 42/10). Part of the distribution of this species is included in the Ponikovski kras Regional Park and in the Special Area of Conservation of Huda luknja (SAC SI3000224).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, natural history, ecology and possible threats of the species would be needed.

Troglohyphantes dominici Pesarini, 1988

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Italy
Map of records (Google Earth): 

Suppl. material 16

Basis of EOO and AOO: Species Distribution Model

Basis (narrative)

Multiple collection sites are known for this species. Therefore, it was possible to perform species distribution modelling to predict its potential range with confidence limits. See Methods for details.

Min Elevation/Depth (m): 338
Max Elevation/Depth (m): 2200

Range description

This species has been found in several localities on the Bergamasque Alps and Prealps (Lombardia, northern Italy) (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 1056-1859,1241
Trend: Stable

Justification for trend

This species has been mainly found in shallow subterranean and epigean environments. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. dominici is not expected to undergo significant reduction in the next future. A deeper study on the impacts of climate change on this species is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Area of occupancy

AOO (km2): 840-1632,1028
Trend: Stable

Justification for trend

This species has been mainly found in shallow subterranean and epigean environments. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. dominici is not expected to undergo significant reduction in the next future. A deeper study on the impacts of climate change on this species is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Locations

Number of locations: Not applicable

Justification for number of locations

No known threats to this species.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Stable

Justification for trend

There are no currently known threats to the species.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: No

Habitat (narrative)

This species has been found in both shallow subterranean and epigean habitats, such as rocky lands, alpine prairies, Rhododendron scrublands, at high altitudes up to 2,200 m.

Trend in extent, area or quality?: Stable
Habitat importance: Major Importance
Habitats: 
  • 3.4. Shrubland - Temperate
  • 4.4. Grassland - Temperate
  • 6. Rocky areas (e.g. inland cliffs, mountain peaks)
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 2.2 mm
Generation length (yr): 2
Dependency of single sp?: No

Ecology and traits (narrative)

Not much is known about the ecology and life history of this species. This spider shows minor specialisation to subterranean life (Mammola et al. 2022a).

Threats

Threat type: Past
Threats:
  • 12. Other options - Other threat

Justification for threats

The existence of direct threats is unknown for this species.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection
  • 2.1. Land/water management - Site/area management

Justification for conservation actions

This species has been recorded within the Natura 2000 network (SAC IT2060009 Val Nossana - Cima di Grem, SPA IT2060401 Parco Regionale Orobie Bergamasche).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, natural history, ecology and possible threats of the species would be needed.

Troglohyphantes excavatus Fage, 1919

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global
Figure(s) or Photo(s): 

Fig. 5

Figure 5.  

Troglohyphantes excavatus Fage, 1919. Photo credit: Martina Pavlek.

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Croatia
  • Slovenia
  • Austria
  • Italy
Map of records (Google Earth): 

Suppl. material 17

Basis of EOO and AOO: Species Distribution Model

Basis (narrative)

Multiple collection sites are recorded for this species. Therefore, it was possible to perform species distribution modelling to predict its potential range with confidence limits. See Methods for details.

Min Elevation/Depth (m): 156
Max Elevation/Depth (m): 1500

Range description

This species has a wide distribution encompassing most of Slovenia and northern Croatia. It has also been recorded in the southern part of Carinthia (southern Austria) and in the area of Trieste in Friuli-Venezia Giulia (north-eastern Italy) (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 26045-37659,31029
Trend: Stable

Justification for trend

Troglohyphantes excavatus has been recorded in a wide range of habitats, both hypogean and epigean. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. excavatus is not expected to undergo significant reduction in the near future. A deeper study on the impacts of climate change on this species is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Area of occupancy

AOO (km2): 11712-21912,16100
Trend: Stable

Justification for trend

Troglohyphantes excavatus has been recorded in a wide range of habitats, both hypogean and epigean. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. excavatus is not expected to undergo significant reduction in the near future. A deeper study on the impacts of climate change on this species is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Locations

Number of locations: Not applicable

Justification for number of locations

There are no currently known threats to this species.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Stable

Justification for trend

There are no currently known threats to the species.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: No

Habitat (narrative)

In Slovenia, Croatia, and Italy specimens have been mainly collected in subterranean environments, both in deep caves and close to cave entrance, but also in shallow subterranean habitats, under big stones, usually in forests. On the contrary, in Austria this species has been recorded from surface localities, in moss and meadows, in spruce or mixed forests and on stream banks in forests.

Trend in extent, area or quality?: Stable

Justification for trend

The habitats colonised by T. excavatus are as yet not threatened by direct human activities.

Habitat importance: Major Importance
Habitats: 
  • 1.4. Forest - Temperate
  • 5.1. Wetlands (inland) - Permanent Rivers/Streams/Creeks (includes waterfalls)
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 2.6 mm
Generation length (yr): 2
Dependency of single sp?: No

Ecology and traits (narrative)

This spider shows minor morphological specialisation to subterranean life (Mammola et al. 2022a). Specimens display high variability in body colouration, ranging from sooty black to pale yellow-orange (Deeleman-Reinhold 1978).

Threats

Threat type: Past
Threats:
  • 12. Other options - Other threat

Justification for threats

The existence of threats is unknown for this species.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection
  • 2.1. Land/water management - Site/area management

Justification for conservation actions

The potential distribution of T. excavatus is covered by several national parks, protected areas, and sites of the Natura 2000 network. In Austria, this species is listed in the category R of the Red List of endangered spiders for Carinthia (Komposch and Steinberger 1999). In addition, this species figures in the 59th Regulation of the Carinthian State Government of 2015 (LGBl. Nr. 59/2015) and it is fully protected from capture, collection, killing, and disturbance according to the Carinthian Nature Conservation Act 2002 (LGBl. Nr. 79/2002).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, ecology, life cycle and possible threats throughout the range would be needed.

Troglohyphantes exul Thaler, 1987

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Italy
Map of records (Google Earth): 

Suppl. material 18

Basis of EOO and AOO: Observed

Basis (narrative)

This spider is known exclusively from the type locality, where it has been repeatedly collected. In light of the high subterranean specialisation of this species and in view of the intensive sampling conducted in other caves in the same area, it is hardly expected that the range could be significantly expanded by new findings.

Min Elevation/Depth (m): 442
Max Elevation/Depth (m): 442

Range description

This species is known only from Cava di Sant'Ambrogio di Valpolicella, in the Lessini Mountains (province of Verona, Veneto, north-eastern Italy) (see Suppl. material 67).

Extent of occurrence

EOO (km2): 4
Trend: Decline (inferred)

Justification for trend

The single cave where this species was found is threatened by quarrying activities, which are expected to cause changes in microclimatic conditions and decrease of habitat quality. In addition, according to Mammola et al. (2018a), climate change will significantly affect the distribution of subterranean specialised Troglohyphantes in the future. Moreover, given the low tolerance to habitat changes of these species as well as their very low dispersal ability, a possible extreme reduction of the geographic range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Area of occupancy

AOO (km2): 4
Trend: Decline (inferred)

Justification for trend

The single cave where this species was found is threatened by quarrying activities, which are expected to cause changes in microclimatic conditions and decrease of habitat quality. In addition, according to Mammola et al. (2018a), climate change will significantly affect the distribution of subterranean specialised Troglohyphantes in the future. Moreover, given the low tolerance to habitat changes of these species as well as their very low dispersal ability, a possible extreme reduction of the geographic range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Locations

Number of locations: 1

Justification for number of locations

This species is known only from a single location, currently subjected to quarrying activities, which are likely to represent a major threat to the survival of the species. Moreover, the cave where this species occurs is exposed to possible changes in subterranean microclimatic conditions due to both quarrying activities and future climate change (see Mammola et al. 2018a).

Trend: Stable

Population

Number of individuals: Unknown
Trend: Decline (inferred)

Justification for trend

In view of the reduced thermal tolerance of highly subterranean adapted Troglohyphantes (Mammola et al. 2019a), alterations of the microclimatic conditions of the habitat due to quarrying activities and due to climate change are expected to impact the whole population of this species.

Basis for decline: 
  • (c) a decline in area of occupancy, extent of occurrence and/or quality of habitat
Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Population Information (Narrative)

No estimates of population size exist.

Subpopulations

Number of subpopulations: 1
Trend: Stable

Justification for trend

For this species we identified a single subpopulation.

Habitat

System: Terrestrial
Habitat specialist: Yes

Habitat (narrative)

This species has been found in an artificial subterranean habitat. Specimens have been collected in areas of complete darkness, were they are rather abundant.

Trend in extent, area or quality?: Decline (inferred)

Justification for trend

The nearby quarrying activities may cause environmental alterations of the cave where this species occurs. In addition, as seen in Mammola et al. (2018a) for the western alpine Troglohyphantes species, a drastic decline in the habitat suitability of T. exul as a consequence of climate change is expected.

Habitat importance: Major Importance
Habitats: 
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 3 mm
Generation length (yr): 4
Dependency of single sp?: No

Ecology and traits (narrative)

This species shows a high degree of specialisation to deep subterranean habitats, with absence of pigmentation and regression of the eyes (Mammola et al. 2022a).

Threats

Threat type: Ongoing
Threats:
  • 3.2. Energy production & mining - Mining & quarrying
Threat type: Future
Threats:
  • 11.1. Climate change & severe weather - Habitat shifting & alteration
  • 11.2. Climate change & severe weather - Droughts
  • 11.3. Climate change & severe weather - Temperature extremes

Justification for threats

This species is potentially exposed due to its extremely narrow geographic distribution range and its presumably low dispersal capacity. Given the low tolerance to habitat changes of this subterranean organism, changes in the internal microclimate caused by the quarrying activities in the area of Cava di Sant'Ambrogio di Valpolicella may interfere with the species’ survival. Moreover, as seen for the species of the genus Troglohyphantes of the Western Alps (Mammola et al. 2018a), climate warming is expected to reduce the currently suitable habitat for this spider.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection
Conservation action type: Needed
Conservation actions:
  • 2.1. Land/water management - Site/area management

Justification for conservation actions

Cava di Sant'Ambrogio di Valpolicella falls within the Special Area of Conservation of Monte Pastello (SAC IT3210021). However, there are no conservation measures in place for this species. This species may benefit from effective protection with strategies aiming to reduce the environmental impacts of the nearby quarrying activities.

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats
  • 3.1. Monitoring - Population trends
  • 3.4. Monitoring - Habitat trends

Justification for research needed

Research on basic information such as distribution, ecology, life cycle and possible threats throughout the range would be needed. Monitoring of population and habitat are important to confirm future trends and to assess the impacts of the nearby quarrying activities.

Troglohyphantes fagei Roewer, 1931

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Germany
  • Austria
  • Italy
Map of records (Google Earth): 

Suppl. material 19

Basis of EOO and AOO: Species Distribution Model

Basis (narrative)

Multiple collection sites are recorded for this species. Therefore, it was possible to perform species distribution modelling to predict its potential range with confidence limits. See Methods for details.

Min Elevation/Depth (m): 164
Max Elevation/Depth (m): 2550

Range description

Troglohyphantes fagei is one of the most widespread species of the genus Troglohyphantes, being widely distributed in the Eastern Alps, from north-eastern Italy to Austria, with a few records from southern Germany (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 50319-69323,60398
Trend: Stable

Justification for trend

This species has been recorded both in hypogean and epigean habitats. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. fagei is not expected to undergo significant reduction in the near future. A deeper study on the impacts of climate change on this species is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Area of occupancy

AOO (km2): 15012-35880,24896
Trend: Stable

Justification for trend

This species has been recorded both in hypogean and epigean habitats. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. fagei is not expected to undergo significant reduction in the near future. A deeper study on the impacts of climate change on this species is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Locations

Number of locations: Not applicable

Justification for number of locations

There are no currently known threats to this species.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Stable

Justification for trend

There are no currently known threats to the species.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: No

Habitat (narrative)

At lower latitudes, this species was mainly collected in caves. At higher latitudes, it has been mainly found in alpine environments above the tree line, such as in rock crevices in alpine screes, in alpine grasslands, and in dwarf mountain pine shrubs.

Trend in extent, area or quality?: Stable

Justification for trend

The habitats colonised by T. fagei are as yet not threatened by direct human activities.

Habitat importance: Major Importance
Habitats: 
  • 1.4. Forest - Temperate
  • 3.4. Shrubland - Temperate
  • 4.4. Grassland - Temperate
  • 6. Rocky areas (e.g. inland cliffs, mountain peaks)
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 2.8 mm
Generation length (yr): 2
Dependency of single sp?: No

Ecology and traits (narrative)

This species shows a minor morphological specialisation to subterranean life (Mammola et al. 2022a). Specimens found in Bus de le Fade cave (north-eastern Italy) are characterised by pronounced microphthalmy (Isaia et al. 2017).

Threats

Threat type: Past
Threats:
  • 12. Other options - Other threat

Justification for threats

The existence of major threats is unknown for this species.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection
  • 2.1. Land/water management - Site/area management

Justification for conservation actions

The potential distribution of this species is covered by several protected areas and sites of the Natura 2000 network. In Germany, due to its extreme rarity in the country, T. fagei was listed in the category R of the national Red List of spiders (Blick et al. 2016) and in the regional Red List of Bavaria (Blick and Scheidler 2004). In Austria, this species figures in the 59th Regulation of the Carinthian State Government of 2015 (LGBl. Nr. 59/2015), and it is fully protected from capture, collection, killing, and disturbance according to the Carinthian Nature Conservation Act 2002 (LGBl. Nr. 79/2002).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, ecology, life cycle and possible threats throughout the range would be needed.

Troglohyphantes fatalis Pesarini, 1988

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Italy
Map of records (Google Earth): 

Suppl. material 20

Basis of EOO and AOO: Species Distribution Model

Basis (narrative)

Multiple collection sites are recorded for this species. Therefore, it was possible to perform species distribution modelling to predict its potential range with confidence limits. See Methods for details.

Min Elevation/Depth (m): 76
Max Elevation/Depth (m): 1815

Range description

This species is known from a few localities in the Prealps of Belluno, in Colli Euganei, and Montello (Veneto, north-eastern Italy) (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 3922-6572,5693
Trend: Stable

Justification for trend

The species has been collected both in epigean and hypogean environments. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. fatalis is not expected to undergo significant reduction in the near future. A deeper study on the impacts of climate change on this species is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Area of occupancy

AOO (km2): 1532-3452,2732
Trend: Stable

Justification for trend

The species has been collected both in epigean and hypogean environments. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. fatalis is not expected to undergo significant reduction in the near future. A deeper study on the impacts of climate change on this species is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Locations

Number of locations: Not applicable

Justification for number of locations

No known threats to this species.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Stable

Justification for trend

There are no currently known threats to the species.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: No

Habitat (narrative)

Troglohyphantes fatalis has been found both in natural and artificial hypogean environments. Specimens have been collected also in surface habitats, such as damp and chestnut woods.

Trend in extent, area or quality?: Stable

Justification for trend

The habitats colonised by T. fatalis are as yet not threatened by direct human activities.

Habitat importance: Major Importance
Habitats: 
  • 1.4. Forest - Temperate
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 2.9 mm
Generation length (yr): 2
Dependency of single sp?: No

Ecology and traits (narrative)

The ecology of this species is unknown.

Threats

Threat type: Past
Threats:
  • 12. Other options - Other threat

Justification for threats

The existence of direct threats is unknown for this species.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection
  • 2.1. Land/water management - Site/area management

Justification for conservation actions

There are several protected areas within the distribution range of this species (EUAP0243 Parco Regionale dei Colli Euganei and SAC/SPA IT3260017 Colli Euganei - Monte Lozzo - Monte Ricco, SAC/SPA IT3230022 Massiccio del Grappa, SAC/SPA IT3220036 Altopiano dei Sette Comuni, SAC/SPA IT3230090 Cima Campo - Monte Celado, SAC IT3240004 Montello). Species distribution modelling predicts that this species could be present in more protected areas.

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, natural history, ecology and possible threats of the species would be needed.

Troglohyphantes gamsi Deeleman-Reinhold, 1978

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Slovenia
Map of records (Google Earth): 

Suppl. material 21

Basis of EOO and AOO: Observed

Basis (narrative)

This species was collected in very few localities. Its low level of subterranean specialisation, possibly reflects a higher dispersal capacity when compared to subterranean specialised species. Consequently, it may be possible that the present known range of this species is underestimated.

Min Elevation/Depth (m): 532
Max Elevation/Depth (m): 988

Range description

This species was recorded only in two localities, in north-western Slovenia: Kristalna jama (Bled) in Upper Carniola, and the tunnel 'Kluža' near Bovec in Slovenian Littoral (see Suppl. material 67).

Extent of occurrence

EOO (km2): 8
Trend: Unknown
Causes ceased?: Unknown
Causes understood?: Unknown
Causes reversible?: Unknown

Area of occupancy

AOO (km2): 8
Trend: Unknown
Causes ceased?: Unknown
Causes understood?: Unknown
Causes reversible?: Unknown

Locations

Number of locations: Unknown

Justification for number of locations

The data available are not enough to estimate the number of locations for this non-specialised species.

Trend: Unknown

Population

Number of individuals: Unknown
Trend: Unknown

Justification for trend

The population size and trend are unknown.

Causes ceased?: Unknown
Causes understood?: Unknown
Causes reversible?: Unknown

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: No

Habitat (narrative)

In the type locality (Kristalna jama), specimens were collected only in the most superficial parts of the cave, among stones and wood debris, in the descending entrance passage.

Trend in extent, area or quality?: Stable
Habitat importance: Major Importance
Habitats: 
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 2.5 mm
Generation length (yr): 2
Dependency of single sp?: No

Ecology and traits (narrative)

Troglohyphantes gamsi is one of the most pigmented Troglohyphantes (Deeleman-Reinhold 1978). This spider shows minor morphological specialisation to subterranean life (Mammola et al. 2022a).

Threats

Threat type: Past
Threats:
  • 12. Other options - Other threat

Justification for threats

Unknown threats.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection
  • 2.1. Land/water management - Site/area management

Justification for conservation actions

Due to its rarity, T. gamsi is considered as potentially threatened and included in the category R of the Slovenian Red List of endangered plant and animal species (Uradni list RS št. 82/02 in 42/10). One of the known localities of this species falls within the Natura 2000 network (SAC SI3000253 Julijske Alps, SPA SI5000019 Julijci).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, natural history, ecology and possible threats of the species would be needed.

Troglohyphantes gestroi Fage, 1933

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Italy
Map of records (Google Earth): 

Suppl. material 22

Basis of EOO and AOO: Observed

Basis (narrative)

Despite the relatively high number of records of this non-specialised species, the distribution range predicted by the models was found to be unreliable by our own expert opinion. In view of this, only the observed distribution range is presented.

Min Elevation/Depth (m): 134
Max Elevation/Depth (m): 1878

Range description

This species is very common in the caves of the Brescia Prealps (Lombardia, northern Italy) while in the province of Bergamo its distribution is confined to the Sebino area and to the high valley of Scalve (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 2380
Trend: Stable

Justification for trend

Troglohyphantes gestroi has been collected both in surface and subterranean environments. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised Troglohyphantes (Mammola et al. 2019a), the distribution range of T. gestroi is not expected to undergo significant reduction in the near future. A deeper study on the current distribution of this species and on the potential impacts of climate change is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Area of occupancy

AOO (km2): 140
Trend: Stable

Justification for trend

Troglohyphantes gestroi has been collected both in surface and subterranean environments. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised Troglohyphantes (Mammola et al. 2019a), the distribution range of T. gestroi is not expected to undergo significant reduction in the near future. A deeper study on the current distribution of this species and on the potential impacts of climate change is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Locations

Number of locations: Not applicable

Justification for number of locations

There are no currently known threats to this species.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Stable

Justification for trend

There are no currently known threats to the species.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: No

Habitat (narrative)

This species has been mainly collected in natural and artificial caves, but it also occurs in epigean environments such as fir woods and open habitats.

Trend in extent, area or quality?: Stable

Justification for trend

The habitats colonised by T. gestroi are as yet not threatened by direct human activities.

Habitat importance: Major Importance
Habitats: 
  • 1.4. Forest - Temperate
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 4.1 mm
Generation length (yr): 2
Dependency of single sp?: No

Ecology and traits (narrative)

Not much is known about the ecology and life history of this species. This spider shows minor morphological specialisation to subterranean life (Mammola et al. 2022a).

Threats

Threat type: Past
Threats:
  • 12. Other options - Other threat

Justification for threats

This species is potentially exposed due to its limited geographic distribution range. However, the existence of direct threats is unknown for this species.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection
  • 2.1. Land/water management - Site/area management

Justification for conservation actions

Part of the distribution of this species falls within several protected areas (SAC IT2060004 Alta Val di Scalve, SPA IT2060401 Parco Regionale Orobie Bergamasche, SAC IT2070018 Altopiano di Cariadeghe).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, natural history, ecology and possible threats of the species would be needed.

Troglohyphantes giachinoi Isaia & Mammola, 2018

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Italy
Map of records (Google Earth): 

Suppl. material 23

Basis of EOO and AOO: Observed

Basis (narrative)

There are only two records known for this spider, both referring to the MSS (Milieu Souterrain Superficiel, see Mammola et al. 2016) habitat. It may be possible that the species occurs in other localities in the area. The known distribution range should be taken with caution.

Min Elevation/Depth (m): 839
Max Elevation/Depth (m): 1332

Range description

This species is known only from MSS habitat in the area of the hypogean complex of the Pugnetto caves, in the municipality of Mezzenile, and from the Natural Park of Colle del Lys (Province of Torino, Piemonte, north-western Italy) (see Suppl. material 67).

Extent of occurrence

EOO (km2): 8
Trend: Decline (inferred)

Justification for trend

According to Mammola et al. (2018a), climate change will significantly affect the distribution of subterranean specialised Troglohyphantes in the future. Moreover, given the low tolerance to habitat changes of these species as well as their very low dispersal ability, a possible extreme reduction of the geographic range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Area of occupancy

AOO (km2): 8
Trend: Decline (inferred)

Justification for trend

According to Mammola et al. (2018a), climate change will significantly affect the distribution of subterranean specialised Troglohyphantes in the future. Moreover, given the low tolerance to habitat changes of these species as well as their very low dispersal ability, a possible extreme reduction of the geographic range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Locations

Number of locations: 1

Justification for number of locations

This species has been recorded in two localities, which are interpreted as a single location as they are both affected by changes in subterranean microclimatic conditions due to climate change.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Decline (inferred)

Justification for trend

In view of the reduced thermal tolerance of subterranean specialised Troglohyphantes species (Mammola et al. 2019a), alterations of the microclimatic conditions of the habitat due to climate change are expected to impact the whole population of this species.

Basis for decline: 
  • (c) a decline in area of occupancy, extent of occurrence and/or quality of habitat
Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Subpopulations

Number of subpopulations: 2
Trend: Decline (inferred)

Justification for trend

Because of the adaptation to the subterranean habitat and the possible consequent narrow thermal tolerance of this species, likely hampering dispersal through non-subterranean habitats, each occurrence reasonably represents a single isolated subpopulation. Accordingly, for this species we identified two subpopulations: the first one occurring in the Pugnetto hypogean complex, in the Lanzo Valleys (Northwestern Alps), and the second subpopulation in the Natural Park of Colle del Lys, an alpine pass located between the lower Valle di Susa and Valle di Viù (Graian Alps). These subpopulations are likely to be impacted by climate change.

Habitat

System: Terrestrial
Habitat specialist: Yes

Habitat (narrative)

Specimens of T. giachinoi were collected in MSS habitat, using subterranean sampling devices installed at depths between 0.40 and 0.80 m and pitfall traps placed in deep beech forest leaf litter [see Mammola et al. (2017) for more details on the habitat]. All the traps were installed at an altitude between 800 and 870 m. Material from the Natural Park of Colle del Lys, was collected by Konrad Thaler in 1972–1973 in unspecified habitat (see Mammola et al. 2018c).

Trend in extent, area or quality?: Decline (inferred)

Justification for trend

MSS habitats, like other superficial subterranean habitats, are likely to be affected by the global temperature increase. It is expected that the temperature increase in superficial subterranean habitats will parallel the external one almost synchronically. Compared with the deep subterranean sectors, effects on the fauna in superficial subterranean habitats are expected to be more immediate (Mammola et al. 2019b). Accordingly, a reduction in the future geographic distribution range of T. giachinoi is expected.

Habitat importance: Major Importance
Habitats: 
  • 7.2. Caves and Subterranean Habitats (non-aquatic) - Other Subterranean Habitats

Ecology

Size: 3 mm
Generation length (yr): 4
Dependency of single sp?: No

Ecology and traits (narrative)

Troglohyphantes giachinoi is among the smaller species of alpine Troglohyphantes, and its short legs and overall small body size may reflect a specialisation for inhabiting small habitat pores, such as the air-filled spaces in the MSS, deep leaf litter, and soil strata. Although this species co-exists with other two Troglohyphantes (T. bornensis and T. lucifuga) in the same hypogean complex, they exploit different habitats (Mammola et al. 2018c).

Threats

Threat type: Future
Threats:
  • 11.1. Climate change & severe weather - Habitat shifting & alteration
  • 11.2. Climate change & severe weather - Droughts
  • 11.3. Climate change & severe weather - Temperature extremes

Justification for threats

This species is potentially exposed due to its extremely narrow geographic distribution range and its low dispersal capacity. Superficial network of underground fissures where T. giachinoi occurs, are likely to be affected by the global temperature increase, which is expected to impact the current suitability of this adapted species. Compared with the deep subterranean sectors, effects of temperature increase on the shallow subterranean fauna are expected to be more immediate (Mammola et al. 2019b).

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection
  • 2.1. Land/water management - Site/area management

Justification for conservation actions

The distribution range of this species is included in a Special Area of Conservation (SAC IT1110048 Grotte del Pugnetto) and in a Regional Park (EUAP0883 Parco Naturale del Colle del Lys).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, natural history, ecology and possible threats of the species would be needed.

Troglohyphantes gracilis Fage, 1919

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Slovenia
Map of records (Google Earth): 

Suppl. material 24

Basis of EOO and AOO: Observed

Basis (narrative)

In light of its high level of subterranean specialisation, we assume that the known records of T. gracilis are good proxies for defining the AOO and EOO of this species.

Min Elevation/Depth (m): 345
Max Elevation/Depth (m): 577

Range description

This species has been collected in three caves (Podpeška jama, Pasjica pri Predolah, and Jama pod cesto) in Lower Carniola (Central Slovenia) (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 136
Trend: Decline (inferred)

Justification for trend

According to Mammola et al. (2018a), climate change will significantly affect the distribution of subterranean specialised Troglohyphantes in the future. Moreover, given the low tolerance to habitat changes of these species as well as their very low dispersal ability, a possible extreme reduction of the geographic range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Area of occupancy

AOO (km2): 12
Trend: Decline (inferred)

Justification for trend

According to Mammola et al. (2018a), climate change will significantly affect the distribution of subterranean specialised Troglohyphantes in the future. Moreover, given the low tolerance to habitat changes of these species as well as their very low dispersal ability, a possible extreme reduction of the geographic range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Locations

Number of locations: 1

Justification for number of locations

Even though this species occurs in three caves, these are interpreted as a single location, as they are all affected by changes in subterranean microclimatic conditions due to climate change.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Decline (inferred)

Justification for trend

In view of the reduced thermal tolerance of subterranean specialised Troglohyphantes (Mammola et al. 2019a), alterations of the microclimatic conditions of the habitat due to climate change are expected to impact the whole population of this species.

Basis for decline: 
  • (c) a decline in area of occupancy, extent of occurrence and/or quality of habitat
Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Subpopulations

Number of subpopulations: 3
Trend: Decline (inferred)

Justification for trend

Because of the adaptation to the subterranean habitat and of the narrow physiological tolerance of this species, likely hampering dispersal through non-subterranean environments, each locality can reasonably host a single isolated subpopulation. Accordingly, for this species we identified three different subpopulations, corresponding to the three caves where the species has been collected. These subpopulation are likely to be impacted by climate change.

Habitat

System: Terrestrial
Habitat specialist: Yes

Habitat (narrative)

There is poor information on the habitat of this species. Specimens have been collected in caves.

Trend in extent, area or quality?: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for the western alpine species of Troglohyphantes, a drastic decline in the habitat suitability of T. gracilis as a consequence of climate change is also expected.

Habitat importance: Major Importance
Habitats: 
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 3.3 mm
Generation length (yr): 4
Dependency of single sp?: No

Ecology and traits (narrative)

This spider shows a high degree of specialisation to subterranean life, with absence of pigmentation (Mammola et al. 2022a).

Threats

Threat type: Future
Threats:
  • 11.1. Climate change & severe weather - Habitat shifting & alteration
  • 11.2. Climate change & severe weather - Droughts
  • 11.3. Climate change & severe weather - Temperature extremes

Justification for threats

This species is potentially exposed due to its extremely narrow geographic distribution range and its presumably low dispersal capacity. As seen for the species of the genus Troglohyphantes of the Western Alps (Mammola et al. 2018a), climate warming is expected to reduce the currently suitable habitat for this spider.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection
  • 2.1. Land/water management - Site/area management

Justification for conservation actions

This species was listed in the first IUCN Red List (IUCN Conservation Monitoring Centre 1986) due to its restricted geographical distribution, and was assessed as Vulnerable in the 1996 IUCN Red List (World Conservation Monitoring Centre 1996a), but its status has not been updated since. In addition, this species figures in the Slovenian national Red List due to its rarity (category R) (Uradni list RS št. 82/02 in 42/10). The locus typicus is protected by the Natura 2000 network (SAC SI3000207 Podpeška jama) and it is not open to the public. Another cave where this species occurs is located in the Special Area of Conservation SAC SI3000232 Notranjski trikotnik, and in the Special Protection Area SPA SI5000002 Snežnik - Pivka.

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats
  • 3.1. Monitoring - Population trends
  • 3.4. Monitoring - Habitat trends

Justification for research needed

Research on basic information such as distribution, ecology, life cycle and possible threats throughout the range would be needed. Monitoring of population and habitat are important to confirm inferred trends.

Troglohyphantes helsdingeni Deeleman-Reinhold, 1978

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Slovenia
  • Austria
Map of records (Google Earth): 

Suppl. material 25

Basis of EOO and AOO: Observed

Basis (narrative)

This species was collected in three localities. Its low level of subterranean specialisation, possibly reflects a higher dispersal capacity when compared to subterranean specialised species. Consequently, it may be possible that the present known range of this species is underestimated.

Min Elevation/Depth (m): 480
Max Elevation/Depth (m): 480

Range description

This species is known from only two localities in Upper Carniola (Slovenia) and from another locality in Carinthia (southern Austria) (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 128
Trend: Stable

Justification for trend

This species is not strictly relegated to deep subterranean habitats. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. helsdingeni is not expected to undergo significant reduction in the near future. A deeper study on the current distribution of this species and on the potential impacts of climate change is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Area of occupancy

AOO (km2): 12
Trend: Stable

Justification for trend

This species is not strictly relegated to deep subterranean habitats. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. helsdingeni is not expected to undergo significant reduction in the near future. A deeper study on the current distribution of this species and on the potential impacts of climate change is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Locations

Number of locations: Not applicable

Justification for number of locations

No known threats to this species.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Stable

Justification for trend

There are no currently known threats to the species.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: No

Habitat (narrative)

This species was collected in small mammal burrows in mixed forest (Fagus-Castaneus). No additional information about the habitat was provided.

Trend in extent, area or quality?: Unknown
Habitat importance: Major Importance
Habitats: 
  • 1.4. Forest - Temperate
  • 7.2. Caves and Subterranean Habitats (non-aquatic) - Other Subterranean Habitats

Ecology

Size: 2.3 mm
Generation length (yr): 2
Dependency of single sp?: No

Ecology and traits (narrative)

This spider shows minor morphological adaptations to the subterranean life (Mammola et al. 2022a).

Threats

Threat type: Past
Threats:
  • 12. Other options - Other threat

Justification for threats

The existence of threats is unknown for this species.

Conservation

Conservation action type: In Place

Justification for conservation actions

Due to its rarity, T. helsdingeni was considered as potentially threatened and listed in the category R of the Slovenian Red List (Uradni list RS št. 82/02 in 42/10), and in the category G (generally threatened) of the Red List of endangered spiders for Carinthia (Komposch and Steinberger 1999). In addition, this species figures in the 59th Regulation of the Carinthian State Government of 2015 (LGBl. Nr. 59/2015), among the species that are fully protected from capture, collection, killing, and disturbance according to the Carinthian Nature Conservation Act 2002 (LGBl. Nr. 79/2002).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, natural history, ecology and possible threats of the species would be needed.

Troglohyphantes henroti Dresco, 1956

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • France
Map of records (Google Earth): 

Suppl. material 26

Basis of EOO and AOO: Observed

Basis (narrative)

This species has been found in a few localities. Due to the limited number of surveys carried out in this area, it seems likely that the species may occur elsewhere nearby. The known distribution range should be taken with caution.

Min Elevation/Depth (m): 1095
Max Elevation/Depth (m): 1280

Range description

This species is known from a few localities of the departments of Drôme and Isère (Auvergne-Rhône-Alpes, south-eastern France) (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 19
Trend: Decline (inferred)

Justification for trend

According to Mammola et al. (2018a), climate change will significantly affect the distribution of subterranean specialised Troglohyphantes in the future. Moreover, given the low tolerance to habitat changes of these species as well as their very low dispersal ability, a possible extreme reduction of the geographic range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Area of occupancy

AOO (km2): 16
Trend: Decline (inferred)

Justification for trend

According to Mammola et al. (2018a), climate change will significantly affect the distribution of subterranean specialised Troglohyphantes in the future. Moreover, given the low tolerance to habitat changes of these species as well as their very low dispersal ability, a possible extreme reduction of the geographic range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Locations

Number of locations: 1

Justification for number of locations

Even though this species occurs in some caves, these are interpreted as a single location, as they are all affected by changes in subterranean microclimatic conditions due to climate change.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Decline (inferred)

Justification for trend

In view of the reduced thermal tolerance of subterranean specialised Troglohyphantes species (Mammola et al. 2019a), alterations of the microclimatic conditions of the habitat due to climate change are expected to impact the whole population of this species.

Basis for decline: 
  • (c) a decline in area of occupancy, extent of occurrence and/or quality of habitat
Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Subpopulations

Number of subpopulations: 2
Trend: Decline (inferred)

Justification for trend

Because of the adaptation to the subterranean habitat and the narrow thermal tolerance of this species, likely hampering dispersal through non-subterranean habitats, each subpopulation can reasonably occur in a single isolated or few contiguous localities. Accordingly, for this species we identified two subpopulations: a southern subpopulation in the commune of Bouvante, Drôme department, and a northern one occurring in a few caves in the commune of Presles, Isère department. Future climate change is expected to affect both of them.

Habitat

System: Terrestrial
Habitat specialist: Yes

Habitat (narrative)

Troglohyphantes henroti has been collected in hypogean habitats. It has not been specified if in the deep portion or near the entrance, however in caves.

Trend in extent, area or quality?: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for other species of the genus Troglohyphantes of the Western Alps, a drastic decline in the habitat suitability of T. henroti as a consequence of climate change is expected.

Habitat importance: Major Importance
Habitats: 
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 4 mm
Generation length (yr): 4
Dependency of single sp?: No

Ecology and traits (narrative)

Specimens show subterranean specialisation to the hypogean life, namely loss of pigmentation and reduction of the eye apparatus (Mammola et al. 2022a).

Threats

Threat type: Future
Threats:
  • 11.1. Climate change & severe weather - Habitat shifting & alteration
  • 11.2. Climate change & severe weather - Droughts
  • 11.3. Climate change & severe weather - Temperature extremes

Justification for threats

This species is potentially exposed due to its extremely narrow geographic distribution range and its presumably low dispersal capacity. As seen for the Troglohyphantes species of the Western Alps (Mammola et al. 2018a), climate warming is expected to reduce the currently suitable habitat for this spider.

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, ecology, life cycle and possible threats throughout the range would be needed.

Troglohyphantes iulianae Brignoli, 1971

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Italy
Map of records (Google Earth): 

Suppl. material 27

Basis of EOO and AOO: Observed

Basis (narrative)

This subterranean specialised species was collected in a few localities spread in a relatively wide range. Consequently, it may be possible that the present known distribution range of this species is underestimated.

Min Elevation/Depth (m): 200
Max Elevation/Depth (m): 1380

Range description

This species has been recorded in a few collection sites spread in a wide distribution range, spanning from the Southwestern Alps to the Tuscanian Apennines (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 8754
Trend: Decline (inferred)

Justification for trend

According to Mammola et al. (2018a), climate change will significantly affect the distribution of subterranean specialised Troglohyphantes in the future. Moreover, given the low tolerance to habitat changes of these species as well as their very low dispersal ability, a possible extreme reduction of the geographic range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Area of occupancy

AOO (km2): 44
Trend: Decline (inferred)

Justification for trend

According to Mammola et al. (2018a), climate change will significantly affect the distribution of subterranean specialised Troglohyphantes in the future. Moreover, given the low tolerance to habitat changes of these species as well as their very low dispersal ability, a possible extreme reduction of the geographic range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Locations

Number of locations: 1

Justification for number of locations

The habitat where this species occurs is affected by changes in subterranean microclimatic conditions due to climate change, which is expected to impact the whole population (see Mammola et al. 2018a).

Trend: Stable

Population

Number of individuals: Unknown
Trend: Decline (inferred)

Justification for trend

In view of the reduced thermal tolerance of subterranean specialised Troglohyphantes species (Mammola et al. 2019a), alterations of the microclimatic conditions of the habitat due to climate change are expected to impact the whole population of this species.

Basis for decline: 
  • (c) a decline in area of occupancy, extent of occurrence and/or quality of habitat
Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: Yes

Habitat (narrative)

This species was found both in caves and in shallow subterranean habitats. Specimens have been mainly collected close to the cave entrance, dwelling among debris. Cave openings are located in Fagus or Castanea woods.

Trend in extent, area or quality?: Decline (inferred)
Habitat importance: Major Importance
Habitats: 
  • 1.4. Forest - Temperate
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 2.4 mm
Generation length (yr): 4
Dependency of single sp?: No

Ecology and traits (narrative)

This spider shows an intermediate degree of morphological specialisation to subterranean life (Mammola et al. 2022a). According to thermal tests, T. iulianae shows a narrow thermal tolerance, reaching 50% mortality at temperature values 2°C above its cave temperature (Mammola et al. 2019a).

Threats

Threat type: Future
Threats:
  • 11.1. Climate change & severe weather - Habitat shifting & alteration
  • 11.2. Climate change & severe weather - Droughts
  • 11.3. Climate change & severe weather - Temperature extremes

Justification for threats

As seen for the western alpine species of the genus Troglohyphantes (Mammola et al. 2018a), climate warming is expected to reduce the currently suitable habitat for this spider.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection
  • 2.1. Land/water management - Site/area management

Justification for conservation actions

This species has been recorded within several protected areas (EUAP0229 Parco Alpi Apuane and SPA IT5120015 Praterie primarie e secondarie delle Apuane, SAC IT1160020 Bosco di Bagnasco, SAC IT1343520 Zona Carsica Cassana, SAC IT5120014 Monte Corchia - Le Panie). Given the wide distribution of this species, it is reasonable to assume that it may occur in other protected areas and sites covered by the Natura 2000 network.

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, ecology, life cycle and possible threats throughout the range would be needed.

Troglohyphantes jamatus Roewer, 1931

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Slovenia
Map of records (Google Earth): 

Suppl. material 28

Basis of EOO and AOO: Observed

Basis (narrative)

In light of its high level of specialisation, we assume that the known records of T. jamatus are good proxies for defining the EOO and AOO of this species.

Min Elevation/Depth (m): 491
Max Elevation/Depth (m): 705

Range description

This highly adapted subterranean species was recorded in seven caves in Inner Carniola and Littoral (western Slovenia) (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 167
Trend: Decline (inferred)

Justification for trend

According to Mammola et al. (2018a), climate change will significantly affect the distribution of subterranean specialised Troglohyphantes in the future. Moreover, given the low tolerance to habitat changes of these species as well as their very low dispersal ability, a possible extreme reduction of the geographic range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Area of occupancy

AOO (km2): 28
Trend: Decline (inferred)

Justification for trend

According to Mammola et al. (2018a), climate change will significantly affect the distribution of subterranean specialised Troglohyphantes in the future. Moreover, given the low tolerance to habitat changes of these species as well as their very low dispersal ability, a possible extreme reduction of the geographic range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Locations

Number of locations: 1

Justification for number of locations

Even though this species occurs in seven caves, these are interpreted as a single location, as they are all affected by changes in subterranean microclimatic conditions due to climate change.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Decline (inferred)

Justification for trend

In view of the reduced thermal tolerance of subterranean specialised Troglohyphantes species (Mammola et al. 2019a), alterations of the microclimatic conditions of the habitat due to climate change are expected to impact the whole population of this species.

Basis for decline: 
  • (c) a decline in area of occupancy, extent of occurrence and/or quality of habitat
Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Subpopulations

Number of subpopulations: 6
Trend: Decline (inferred)

Justification for trend

Because of the adaptation to the subterranean habitat and the narrow thermal tolerance of highly adapted Troglohyphantes, likely hampering dispersal through non-subterranean habitats, each subpopulation of T. jamatus reasonably occurs in a single isolated or few contiguous localities. Accordingly, for this species we identified six subpopulations. These subpopulations are likely to be impacted by climate change.

Habitat

System: Terrestrial
Habitat specialist: Yes

Habitat (narrative)

The species is strictly relegated to cave habitat. No additional information about the habitat was available.

Trend in extent, area or quality?: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for the species of the genus Troglohyphantes of the Western Alps, a drastic decline in the habitat suitability of T. jamatus as a consequence of climate change is also expected.

Habitat importance: Major Importance
Habitats: 
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 3.1 mm
Generation length (yr): 4
Dependency of single sp?: No

Ecology and traits (narrative)

This species shows a high degree of specialisation to deep subterranean habitats, with absence of pigmentation and eye reduction (Mammola et al. 2022a).

Threats

Threat type: Future
Threats:
  • 11.1. Climate change & severe weather - Habitat shifting & alteration
  • 11.2. Climate change & severe weather - Droughts
  • 11.3. Climate change & severe weather - Temperature extremes

Justification for threats

This species is potentially exposed due to its extremely narrow geographic distribution range and its presumably low dispersal capacity. As seen for the Troglohyphantes species of the Western Alps (Mammola et al. 2018a), climate warming is expected to reduce the currently suitable habitat for this spider. One of the caves where the species occurs (Postojna Cave) is opened to tourism (more than 1,000,000 tourists per year). Consequently, a secondary impact for this subpopulation could derive from touristic activities.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection
  • 2.1. Land/water management - Site/area management

Justification for conservation actions

Due to its rarity, this species was considered as potentially threatened and listed in the Slovenian Red List of endangered plant and animal species (Uradni list RS št. 82/02 in 42/10), in the category R. The vast majority of this species' records are located within Special Areas of Conservation (SAC SI3000232 Notranjski trikotnik, SAC SI3000255 Trnovski gozd - Nanos, SAC SI3000256 Krimsko hribovje - Meni).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, ecology, life cycle and possible threats throughout the range would be needed.

Troglohyphantes juris Thaler, 1982

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Italy
Map of records (Google Earth): 

Suppl. material 29

Basis of EOO and AOO: Observed

Basis (narrative)

In light of its high level of subterranean specialisation, we assume that the known records of T. juris are good proxies for defining the EOO and AOO of this species.

Min Elevation/Depth (m): 480
Max Elevation/Depth (m): 801

Range description

Troglohyphantes juris was found in six caves in the Carnic Prealps (Friuli-Venezia Giulia, north-eastern Italy) (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 55
Trend: Decline (inferred)

Justification for trend

According to Mammola et al. (2018a), climate change will significantly affect the distribution of subterranean specialised Troglohyphantes in the future. Moreover, given the low tolerance to habitat changes of these species as well as their very low dispersal ability, a possible extreme reduction of the geographic range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Area of occupancy

AOO (km2): 24
Trend: Decline (inferred)

Justification for trend

According to Mammola et al. (2018a), climate change will significantly affect the distribution of subterranean specialised Troglohyphantes in the future. Moreover, given the low tolerance to habitat changes of these species as well as their very low dispersal ability, a possible extreme reduction of the geographic range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Locations

Number of locations: 1

Justification for number of locations

Even though this species occurs in six caves, these are interpreted as a single location as they are all affected by changes in subterranean microclimatic conditions due to climate change.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Decline (inferred)

Justification for trend

In view of the reduced thermal tolerance of subterranean specialised Troglohyphantes species (Mammola et al. 2019a), alterations of the microclimatic conditions of the habitat due to climate change are expected to impact the whole population of this species.

Basis for decline: 
  • (c) a decline in area of occupancy, extent of occurrence and/or quality of habitat
Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Subpopulations

Number of subpopulations: 3
Trend: Decline (inferred)

Justification for trend

Because of the adaptation to the subterranean habitat and the narrow thermal tolerance of highly adapted Troglohyphantes, likely hampering dispersal through non-subterranean habitats, each subpopulation of T. juris can reasonably occur in a single isolated or few contiguous localities. Accordingly, for this species we identified three subpopulations occurring in the province of Pordenone, in Friuli-Venezia Giulia. These subpopulations are likely to be impacted by climate change.

Habitat

System: Terrestrial
Habitat specialist: Yes

Habitat (narrative)

This species was collected in deep cave habitats. No additional information on the habitat has been provided.

Trend in extent, area or quality?: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for the species of the genus Troglohyphantes occurring in the Western Alps, a drastic decline in the habitat suitability of the T. juris as a consequence of climate change is expected.

Habitat importance: Major Importance
Habitats: 
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 2.7 mm
Generation length (yr): 4
Dependency of single sp?: No

Ecology and traits (narrative)

This spider shows a considerable eye reduction and absence of pigmentation (Mammola et al. 2022a).

Threats

Threat type: Future
Threats:
  • 11.1. Climate change & severe weather - Habitat shifting & alteration
  • 11.2. Climate change & severe weather - Droughts
  • 11.3. Climate change & severe weather - Temperature extremes

Justification for threats

This species is potentially exposed due to its extremely narrow geographic distribution range and its presumably low dispersal capacity. As seen for the Troglohyphantes species of the Western Alps (Mammola et al. 2018a), climate warming is expected to reduce the currently suitable habitat for this spider.

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, ecology, life cycle and possible threats throughout the range would be needed.

Troglohyphantes karawankorum Deeleman-Reinhold, 1978

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Slovenia
  • Austria
Map of records (Google Earth): 

Suppl. material 30

Basis of EOO and AOO: Observed

Basis (narrative)

This species was collected in very few localities. Its low level of subterranean specialisation, together with the high altimetric range observed in its known distribution, possibly reflects a higher dispersal capacity when compared to subterranean specialised species. Consequently, it may be possible that the present known range of this species is underestimated.

Min Elevation/Depth (m): 700
Max Elevation/Depth (m): 1880

Range description

This species is only known from the type locality, Jama na Babi, Jezersko (Upper Carniola, northern Slovenia), and from two localities in Carinthia (southern Austria) (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 12
Trend: Stable

Justification for trend

This species is not strictly relegated to deep subterranean habitats, being collected both at a cave entrance and in epigean habitats. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised Troglohyphantes (Mammola et al. 2019a), the distribution range of T. karawankorum is not expected to undergo significant reduction in the near future. A deeper study on the current distribution of this species and on the potential impacts of climate change is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Area of occupancy

AOO (km2): 12
Trend: Stable

Justification for trend

This species is not strictly relegated to deep subterranean habitats, being collected both at a cave entrance and in epigean habitats. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised Troglohyphantes (Mammola et al. 2019a), the distribution range of T. karawankorum is not expected to undergo significant reduction in the near future. A deeper study on the current distribution of this species and on the potential impacts of climate change is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Locations

Number of locations: Not applicable

Justification for number of locations

No known threats to this species.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Stable

Justification for trend

There are no currently known threats to the species.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: No

Habitat (narrative)

Specimens collected in the type locality, Jama na babi in Upper Carniola, have been found near the entrance of the cave, in a chamber with the floor covered by wood, stony debris, and leaf litter. The specimens from Carinthia have been collected in montane and subalpine zone, among crevices in boulder screes or in alpine grasslands.

Trend in extent, area or quality?: Unknown
Habitat importance: Major Importance
Habitats: 
  • 4.4. Grassland - Temperate
  • 6. Rocky areas (e.g. inland cliffs, mountain peaks)
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 2.8 mm
Generation length (yr): 2
Dependency of single sp?: No

Ecology and traits (narrative)

Specimens show eye regression and absence of pigmentation (Mammola et al. 2022a).

Threats

Threat type: Past
Threats:
  • 12. Other options - Other threat

Justification for threats

This species is potentially exposed due to its extremely narrow geographic distribution range. However, the existence of direct threats to this species is unknown.

Conservation

Conservation action type: In Place

Justification for conservation actions

This species was considered as potentially threatened due to its rarity and included in the category R in the Slovenian Red List (Uradni list RS št. 82/02 in 42/10). Troglohyphantes karawankorum is considered one of the rarest spider species in Austria (Komposch 2009), and figures in the category R of the Red List of endangered spiders for Carinthia (Komposch and Steinberger 1999). In addition, this species figures in the 59th Regulation of the Carinthian State Government of 2015 (LGBl. Nr. 59/2015), and it is fully protected by the Carinthian Nature Conservation Act 2002 (LGBl. Nr. 79/2002).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, ecology, life cycle and possible threats throughout the range would be needed.

Troglohyphantes konradi Brignoli, 1975

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global
Figure(s) or Photo(s): 

Fig. 6

Figure 6.  

Troglohyphantes konradi Brignoli, 1975. Photo credit: Francesco Tomasinelli.

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • France
  • Italy
Map of records (Google Earth): 

Suppl. material 31

Basis of EOO and AOO: Observed

Basis (narrative)

Caves in Western Alps have been extensively sampled, allowing to define EOO and AOO of this species with reasonable confidence.

Min Elevation/Depth (m): 825
Max Elevation/Depth (m): 1493

Range description

This species is known from several caves and military bunkers in the Maritime Alps, between Gesso and Vermenagna Valleys (Piemonte, north-western Italy). Moreover, it was recently found in France, in a blockhouse near Brigue (Provence-Alpes-Côte d'Azur). Detailed occurrences and relative references are in Suppl. material 67.

Extent of occurrence

EOO (km2): 156
Trend: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for other subterranean specialised Troglohyphantes of the Western Alps, climate change is expected to affect the distribution of this species in the future. Given the reduced thermal tolerance of this species and its low dispersal ability (Mammola et al. 2019a), a reduction of its geographic distribution range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Area of occupancy

AOO (km2): 20
Trend: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for other subterranean specialised Troglohyphantes of the Western Alps, climate change is expected to affect the distribution of this species in the future. Given the reduced thermal tolerance of this organism and its low dispersal ability (Mammola et al. 2019a), a reduction of its geographic distribution range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Locations

Number of locations: 1

Justification for number of locations

The habitat where this species occurs is affected by changes in subterranean microclimatic conditions due to climate change, which is expected to impact the whole population (see Mammola et al. 2018a).

Trend: Stable

Population

Number of individuals: Unknown
Trend: Decline (inferred)

Justification for trend

In view of the reduced thermal tolerance of this species (Mammola et al. 2019a), alterations of the microclimatic conditions of the habitat due to climate change are expected to impact the whole population of this species.

Basis for decline: 
  • (c) a decline in area of occupancy, extent of occurrence and/or quality of habitat
Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Subpopulations

Number of subpopulations: 4
Trend: Decline (inferred)

Justification for trend

Because of the subterranean adaptation and the narrow physiological tolerance of this species, hampering dispersal through non-subterranean habitats, each subpopulation reasonably occurs in a single isolated or in a few contiguous localities. Accordingly, for this species we identified four subpopulations in the range, three of them occurring in Valle Vermenagna and Valle Gesso, and a southern isolated subpopulation in the French Maritime Alps. All the subpopulations are likely to be impacted by climate change.

Habitat

System: Terrestrial
Habitat specialist: Yes

Habitat (narrative)

This species has been found at the ground level amid stones, in small interstices or on webs on the walls in caves, military bunkers, and blockhouses. Most of the cave openings are located in beech forests.

Trend in extent, area or quality?: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for other species of the genus Troglohyphantes of the Western Alps, a drastic decline in the habitat suitability of T. konradi as a consequence of climate change is expected.

Habitat importance: Major Importance
Habitats: 
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 3.5 mm
Generation length (yr): 4
Dependency of single sp?: No

Ecology and traits (narrative)

This high subterranean specialised spider is totally depigmented, microphthalmic, and shows a rich spination (Mammola et al. 2022a). According to thermal tests, T. konradi shows a narrow thermal tolerance, reaching 50% mortality at temperature values 1°C above its cave temperature (Mammola et al. 2019a).

Threats

Threat type: Future
Threats:
  • 11.1. Climate change & severe weather - Habitat shifting & alteration
  • 11.2. Climate change & severe weather - Droughts
  • 11.3. Climate change & severe weather - Temperature extremes

Justification for threats

This species is potentially exposed due to its extremely narrow geographic distribution range. As seen for other species of the genus Troglohyphantes of the Western Alps (Mammola et al. 2018a), climate warming is expected to reduce the currently suitable habitat for this spider. Moreover, in view of its reduced thermal tolerance (Mammola et al. 2019a), this species has a limited dispersal ability, which represents an additional concern in face of the ongoing increase of temperature.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection

Justification for conservation actions

Part of the distribution of this species is within the borders of the Special Area of Conservation and Special Protection Area of the Maritime Alps (SAC/SPA IT1160056).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, ecology, life cycle and possible threats throughout the range would be needed.

Troglohyphantes kordunlikanus Deeleman-Reinhold, 1978

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global
Figure(s) or Photo(s): 

Fig. 7

Figure 7.  

Troglohyphantes kordunlikanus Deeleman-Reinhold, 1978. Photo credit: Martina Pavlek.

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Bosnia and Herzegovina
  • Croatia
Map of records (Google Earth): 

Suppl. material 32

Basis of EOO and AOO: Species Distribution Model

Basis (narrative)

Multiple collection sites are recorded for this species. Therefore, it was possible to perform species distribution modelling to predict its potential range with confidence limits. See Methods for details.

Min Elevation/Depth (m): 136
Max Elevation/Depth (m): 1353

Range description

This species has been found in the Primorje-Gorski Kotar, Karlovac, Lika-Senj, and Zadar counties in Croatia, and in north-western Bosnia and Herzegovina (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 18072-27428,19817
Trend: Stable

Justification for trend

This species has been collected in caves and shallow subterranean habitats as well as under stones and in animal burrows in moist leaf litter. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. kordunlikanus is not expected to undergo significant reduction in the near future. A deeper study on the impacts of climate change on this species is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Area of occupancy

AOO (km2): 13328-21464,15368
Trend: Stable

Justification for trend

This species has been collected in caves and shallow subterranean habitats as well as under stones and in animal burrows in moist leaf litter. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. kordunlikanus is not expected to undergo significant reduction in the near future. A deeper study on the impacts of climate change on this species is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Locations

Number of locations: Not applicable

Justification for number of locations

No known threats to this species.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Stable

Justification for trend

There are no currently known threats to the species.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Subpopulations

Number of subpopulations: Unknown
Trend: Stable

Habitat

System: Terrestrial
Habitat specialist: No

Habitat (narrative)

This species has been found on the ceiling and the walls of caves, mainly at no more than 50 meters from the entrance, and in small animal burrows and under stones in forest habitats. In Lika, in the western part of the range, this species was found only in caves. Deeleman-Reinhold (1978) pointed out that in historical times this area was almost completely stripped of the original forest cover, and that the present vegetation consists mainly of Mediterranean shrubs and dry woods of Carpinus or hornbeam-oak, possibly not suitable for this species.

Trend in extent, area or quality?: Stable
Habitat importance: Major Importance
Habitats: 
  • 1.4. Forest - Temperate
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 2.4 mm
Generation length (yr): 2
Dependency of single sp?: No

Ecology and traits (narrative)

Not much is known about the ecology of this species. All the individuals are depigmented (even the ones collected outside the caves), and have normally developed eyes circled with black pigmentation of variable width (Mammola et al. 2022a).

Threats

Threat type: Past
Threats:
  • 12. Other options - Other threat

Justification for threats

This species is potentially exposed due to its restricted geographic distribution range. However, the existence of threats is unknown for this species.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection

Justification for conservation actions

This species has been found in several protected areas and sites of the Natura 2000 network. The species distribution modelling predicts that it could also be present in further protected areas.

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as distribution, ecology, life cycle and possible threats throughout the range would be needed.

Troglohyphantes lanai Isaia & Pantini, 2010

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Italy
Map of records (Google Earth): 

Suppl. material 33

Basis of EOO and AOO: Observed

Basis (narrative)

Caves in Western Alps have been extensively sampled, allowing to define EOO and AOO of this species with reasonable confidence.

Min Elevation/Depth (m): 640
Max Elevation/Depth (m): 864

Range description

This species is restricted to six caves of the Monte Fenera hypogean complex, a limestone cave complex in the Northwestern Alps (province of Vercelli, Piemonte, north-western Italy) (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 8
Trend: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for all the subterranean specialised Troglohyphantes species of the Western Alps, climate change is expected to affect the distribution of this species in the future. Given the reduced thermal tolerance of this organism and its low dispersal ability (Mammola et al. 2019a), a reduction of its geographic distribution range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Area of occupancy

AOO (km2): 8
Trend: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for all the subterranean specialised Troglohyphantes species of the Western Alps, climate change is expected to affect the distribution of this species in the future. Given the reduced thermal tolerance of this organism and its low dispersal ability (Mammola et al. 2019a), a reduction of its geographic distribution range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Locations

Number of locations: 1

Justification for number of locations

The habitat where this species occurs is affected by changes in subterranean microclimatic conditions due to climate change, which is expected to impact the whole population (see Mammola et al. 2018a).

Trend: Stable

Population

Number of individuals: Unknown
Trend: Decline (inferred)

Justification for trend

In view of the reduced thermal tolerance of this species (Mammola et al. 2019a), alterations of the microclimatic conditions of the habitat due to climate change are expected to impact the whole population of this species.

Basis for decline: 
  • (c) a decline in area of occupancy, extent of occurrence and/or quality of habitat
Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Subpopulations

Number of subpopulations: 1
Trend: Stable

Justification for trend

Because of the adaptation to the subterranean habitat and of the narrow thermal tolerance of this species, likely hampering dispersal through non-subterranean habitats, each locality can reasonably host a single isolated subpopulation. Accordingly, for this species we identified a single subpopulation occurring in the Monte Fenera hypogean complex.

Habitat

System: Terrestrial
Habitat specialist: Yes

Habitat (narrative)

Specimens of T. lanai have been found among stony debris in the caves of the complex of Monte Fenera (limestone with intercalated sandstone), in the Pennine Alps (north-western Italy). All caves have openings into beech woods, with a prevalent northerly aspect to the cave opening, The temperatures in the caves are constantly about 9°C (Isaia and Pantini 2010).

Trend in extent, area or quality?: Decline (inferred)

Justification for trend

As seen in Mammola et al. (2018a) for all the subterranean specialised Troglohyphantes of the Western Alps, a drastic decline in the habitat suitability of T. lanai as a consequence of climate change is expected.

Habitat importance: Major Importance
Habitats: 
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 3.1 mm
Generation length (yr): 4
Dependency of single sp?: No

Ecology and traits (narrative)

This species shows particularly remarkable subterranean traits, such as pronounced eye regression and absence of pigmentation (Mammola et al. 2022a). According to thermal tests, T. lanai shows a narrow thermal tolerance, reaching 50% mortality at temperature values 2°C above its cave temperature (Mammola et al. 2019a).

Threats

Threat type: Future
Threats:
  • 11.1. Climate change & severe weather - Habitat shifting & alteration
  • 11.2. Climate change & severe weather - Droughts
  • 11.3. Climate change & severe weather - Temperature extremes

Justification for threats

This species is potentially exposed due to its extremely narrow geographic distribution range and its presumably low dispersal capacity. As seen for other western alpine Troglohyphantes species (Mammola et al. 2018a), climate warming is expected to reduce the currently suitable habitat for this spider.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection

Justification for conservation actions

The species range falls entirely within the Natural Park of Monte Fenera (SAC IT1120003). However, there are no conservation measures in place for this species.

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as natural history, ecology and possible threats of the species would be needed.

Troglohyphantes latzeli Thaler, 1986

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Slovenia
  • Austria
Map of records (Google Earth): 

Suppl. material 34

Basis of EOO and AOO: Observed

Basis (narrative)

This species was collected in very few localities. Its low level of subterranean specialisation, together with the high altimetric range found in its known distribution, possibly reflects a higher dispersal capacity when compared to subterranean specialised species. Consequently, it may be possible that the present known range of this species is underestimated.

Min Elevation/Depth (m): 560
Max Elevation/Depth (m): 1300

Range description

This species has been documented only in a few localities between Carinthia (southern Austria) and Upper Carniola (northern Slovenia) (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 467
Trend: Decline (inferred)

Justification for trend

Habitat loss and land use change due to urbanisation and infrastructure development in some of the localities where this species has been collected (Komposch 2009), indicate the species is likely declining.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: Yes

Area of occupancy

AOO (km2): 46
Trend: Decline (inferred)

Justification for trend

Habitat loss and land use change due to urbanisation and infrastructure development in some of the localities where this species has been collected (Komposch 2009), indicate the species is likely declining.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: Yes

Locations

Number of locations: 2

Justification for number of locations

Two locations, corresponding to the Austrian subpopulations, are threatened by urbanisation and infrastructure development.

Trend: Decline (inferred)

Population

Number of individuals: Unknown
Trend: Decline (inferred)

Justification for trend

The population is threatened by habitat loss and land use change due to urbanisation and infrastructure development in part of its range.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: Yes

Subpopulations

Number of subpopulations: 3
Trend: Decline (inferred)

Justification for trend

Based on the data available, for this species we identified three subpopulations: two of them occurring in southern Austria and one in northern Slovenia. The Austrian subpopulations are affected by habitat loss and land use change due to urban and transport infrastructure development.

Habitat

System: Terrestrial
Habitat specialist: No

Habitat (narrative)

This species has been collected in different habitats in the medium montane belt, from 500 up to 1,300 m, such as pastures, prairies, broadleaf, and conifer forests. It has also been found in rock crevices in boulder fields.

Trend in extent, area or quality?: Decline (inferred)

Justification for trend

Some of the habitats where this species has been found are threatened by urban, industrial, and transport infrastructure development (Komposch 2009).

Habitat importance: Major Importance
Habitats: 
  • 1.4. Forest - Temperate
  • 4.4. Grassland - Temperate
  • 6. Rocky areas (e.g. inland cliffs, mountain peaks)

Ecology

Size: 2.5 mm
Generation length (yr): 2
Dependency of single sp?: No

Ecology and traits (narrative)

This spider shows minor specialisation to subterranean life (Mammola et al. 2022a).

Threats

Threat type: Ongoing
Threats:
  • 1.1. Residential & commercial development - Housing & urban areas
  • 1.2. Residential & commercial development - Commercial & industrial areas
  • 4.1. Transportation & service corridors - Roads & railroads

Justification for threats

This species currently faces threats of habitat loss and land use change due to urbanisation and due to railway and road infrastructure development (Komposch 2009).

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection
  • 2.1. Land/water management - Site/area management

Justification for conservation actions

The records from Slovenia fall within the Special Area of Conservation and Special Protection Area of the Julian Alps (SAC SI3000253, SPA SI5000019). In Austria, T. latzeli has been listed in the 59th Regulation of the Carinthian State Government of 2015 (LGBl. Nr. 59/2015), which amends the Carinthian Nature Conservation Act 2002 (LGBl. Nr. 79/2002).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as natural history, ecology and possible threats of the species would be needed.

Troglohyphantes lessinensis Caporiacco, 1936

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Italy
Map of records (Google Earth): 

Suppl. material 35

Basis of EOO and AOO: Observed

Basis (narrative)

Despite the relatively high number of records of this non-specialised species, the species distribution predicted by the models was found to be unreliable by our own expert opinion. In view of this, only the observed distribution range is presented.

Min Elevation/Depth (m): 197
Max Elevation/Depth (m): 2599

Range description

This species has been found in several caves in the Lessini Mountains, Monte Baldo, and other localities of the Venetian Prealps, and in the southern Trentino-Alto Adige (north-eastern Italy). New records were recently collected in epigean habitats in the Brenta Dolomites, extending considerably the distribution of this species northwards (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 2269
Trend: Stable

Justification for trend

This species has been mainly found in caves, but several specimens have been recorded in epigean habitats. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. lessinensis is not expected to undergo significant reduction in the near future. A deeper study on the current distribution of this species and on the potential impacts of climate change is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Area of occupancy

AOO (km2): 104
Trend: Stable

Justification for trend

This species has been mainly found in caves, but several specimens have been recorded in epigean habitats. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised species of Troglohyphantes (Mammola et al. 2019a), the distribution range of T. lessinensis is not expected to undergo significant reduction in the near future. A deeper study on the current distribution of this species and on the potential impacts of climate change is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Locations

Number of locations: Not applicable

Justification for number of locations

No known threats to this species.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Stable

Justification for trend

There are no currently known threats to the species.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: No

Habitat (narrative)

Troglohyphantes lessinensis was collected mainly in natural and artificial hypogean habitats. However, specimens have been recently found also in high altitude rocky lands and alpine screes.

Trend in extent, area or quality?: Stable

Justification for trend

The habitats colonised by T. lessinensis are as yet not threatened by direct human activities.

Habitat importance: Major Importance
Habitats: 
  • 1.4. Forest - Temperate
  • 6. Rocky areas (e.g. inland cliffs, mountain peaks)
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 3.2 mm
Generation length (yr): 2
Dependency of single sp?: No

Ecology and traits (narrative)

Specimens are characterised by a pronounced microphthalmy (Mammola et al. 2022a).

Threats

Threat type: Past
Threats:
  • 12. Other options - Other threat

Justification for threats

This species is potentially exposed due to its restricted geographic distribution range. However, the existence of threats is unknown for this species.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection
  • 2.1. Land/water management - Site/area management

Justification for conservation actions

This species has been found within the Natura 2000 network (SAC/SPA IT3210040 Monti Lessini - Pasubio - Piccole Dolomiti Vicentine, SAC/SPA IT3210039 Monte Baldo Ovest, SAC/SPA IT3210041 Monte Baldo Est, EUAP0930 and SAC IT3120177 Dolomiti di Brenta, SPA IT3120159 Brenta).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats

Justification for research needed

Research on basic information such as natural history, ecology and possible threats of the species would be needed.

Troglohyphantes liburnicus Caporiacco, 1927

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global
Figure(s) or Photo(s): 

Fig. 8

Figure 8.  

Troglohyphantes liburnicus Caporiacco, 1927. Photo credit: Helena Bilandžija.

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Croatia
Map of records (Google Earth): 

Suppl. material 36

Basis of EOO and AOO: Observed

Basis (narrative)

In light of its subterranean specialisation, we assume that the known records of T. liburnicus are good proxies for defining the AOO and EOO of this species.

Min Elevation/Depth (m): 132
Max Elevation/Depth (m): 929

Range description

Troglohyphantes liburnicus has been collected in several caves in the Primorje-Gorski Kotar county and in the northern part of the Island of Cres (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 727
Trend: Decline (inferred)

Justification for trend

Most of the potential distribution of this species corresponds to the coastal area of the Croatian Littoral, where the urban infrastructure development and the industrial pollution are resulting in large-scale alterations of the natural environment, which affect the habitat of this species (Ozimec et al. 2009). In addition, according to Mammola et al. (2018a), climate change will significantly affect the distribution of subterranean specialised Troglohyphantes in the future. Moreover, given the low tolerance to habitat changes of these species as well as their very low dispersal ability, a possible extreme reduction of the geographic range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Area of occupancy

AOO (km2): 64
Trend: Decline (inferred)

Justification for trend

Most of the potential distribution of this species corresponds to the coastal area of the Croatian Littoral, where the urban infrastructure development and the industrial pollution are resulting in large-scale alterations of the natural environment, which affect the habitat of this species (Ozimec et al. 2009). In addition, according to Mammola et al. (2018a), climate change will significantly affect the distribution of subterranean specialised Troglohyphantes in the future. Moreover, given the low tolerance to habitat changes of these species as well as their very low dispersal ability, a possible extreme reduction of the geographic range is expected in the future.

Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Locations

Number of locations: 1

Justification for number of locations

Some of the caves where this species occurs are located in an area heavily impacted by urban development, tourism and industrial pollution. However, all the caves where this species occurs are affected by changes in subterranean microclimatic conditions due to climate change, which is considered the most serious plausible threat expected to impact the whole population (see Mammola et al. 2018a).

Trend: Stable

Population

Number of individuals: Unknown
Trend: Decline (inferred)

Justification for trend

Habitat loss and degradation due to urban development and pollution affects the population of T. liburnicus. In addition, in view of the reduced thermal tolerance of subterranean specialised Troglohyphantes species (Mammola et al. 2019a), alterations of the microclimatic conditions of the habitat due to climate change are expected to impact the whole population of this species.

Basis for decline: 
  • (c) a decline in area of occupancy, extent of occurrence and/or quality of habitat
Causes ceased?: No
Causes understood?: Yes
Causes reversible?: No

Subpopulations

Number of subpopulations: 3-6
Trend: Decline (inferred)

Justification for trend

Because of the adaptation to the subterranean habitat and the narrow thermal tolerance of highly adapted Troglohyphantes, likely hampering dispersal through non-subterranean habitats, each subpopulation of T. liburnicus reasonably occurs in a single isolated or few contiguous localities. Accordingly, for this species we identified three to six subpopulations. Urbanisation and industrialisation are affecting most of them throughout this species' range.

Habitat

System: Terrestrial
Habitat specialist: No

Habitat (narrative)

This species has been found both in the twilight zone and in the deepest part of the caves, in the recesses or between rocks and stalagmites on the ground. In the pit Jama kod Škalnice, specimens occurred in webs on a steep slope covered with wood debris and pieces of rock.

Trend in extent, area or quality?: Decline (inferred)

Justification for trend

Most of the localities where this species occurs are threatened by habitat loss and degradation due to urban infrastructure development and residential and industrial pollution (Ozimec et al. 2009). Moreover, as seen in Mammola et al. (2018a) for other species of the genus Troglohyphantes of the Western Alps, a drastic decline in the habitat suitability of T. liburnicus as a consequence of climate change is expected.

Habitat importance: Major Importance
Habitats: 
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 4.5 mm
Generation length (yr): 4
Dependency of single sp?: No

Ecology and traits (narrative)

Specimens show pronounced morphological specialisation to the subterranean habitat, such as eyes regression, leg elongation, and absence of pigmentation (Mammola et al. 2022a).

Threats

Threat type: Ongoing
Threats:
  • 1.1. Residential & commercial development - Housing & urban areas
  • 1.2. Residential & commercial development - Commercial & industrial areas
  • 9.1. Pollution - Domestic & urban waste water
  • 9.2. Pollution - Industrial & military effluents
Threat type: Future
Threats:
  • 11.1. Climate change & severe weather - Habitat shifting & alteration
  • 11.2. Climate change & severe weather - Droughts
  • 11.3. Climate change & severe weather - Temperature extremes

Justification for threats

This species is potentially exposed due to its extremely narrow geographic distribution range and its presumably low dispersal capacity. Habitat loss and degradation due to urban infrastructure development and due to pollution from commercial and industrial facilities, represents an ongoing threat to T. liburnicus. Pollution by solid and liquid municipal waste from illegal landfills causes the degradation of cave ecosystems (Ozimec et al. 2009). The type locality is located near both the railway and the major road connecting the city of Rijeka with the Slovenian border. This area, corresponding to the municipality of Matulji, is highly urbanized, with the urban infrastructure growth increasing rapidly in recent years. In addition, as seen for other species of the genus Troglohyphantes of the Western Alps (Mammola et al. 2018a), climate warming is expected to reduce the currently suitable habitat for this spider.

Conservation

Conservation action type: In Place
Conservation actions:
  • 1.1. Land/water protection - Site/area protection
  • 1.2. Land/water protection - Resource & habitat protection
Conservation action type: Needed
Conservation actions:
  • 2.1. Land/water management - Site/area management
  • 2.3. Land/water management - Habitat & natural process restoration

Justification for conservation actions

This species is listed as Vulnerable in the Red Book of Croatian Cave Dwelling Fauna (Ozimec et al. 2009). As a cave species, T. liburnicus is strictly legally protected according to the existing Nature Protection Act (Official Gazette 70/05, NN 139/2008), which prohibits collection, killing, and disturbance of specimens and destruction of their habitats without permission from the Ministry in charge of nature protection. The distribution of this species falls within several protected areas (SPA HR1000033 Kvarnerski otoci, SCI HR2001358 Otok Cres, SPA HR1000018 Učka i Ćićarija, SCI HR2000601 Park prirode Učka, SCI/SPA HR5000019 Gorski kotar i sjeverna Lika).

Other

Use type: International
Ecosystem service type: Important
Research needed:
  • 1.2. Research - Population size, distribution & trends
  • 1.3. Research - Life history & ecology
  • 1.5. Research - Threats
  • 3.1. Monitoring - Population trends
  • 3.4. Monitoring - Habitat trends

Justification for research needed

Research on basic information such as natural history, ecology and possible threats of the species would be needed. Population status and habitat quality should be monitored.

Troglohyphantes lucifer Isaia, Mammola & Pantini, 2017

Species information

Taxonomy

Kingdom Phylum Class Order Family
Animalia Arthropoda Arachnida Araneae Linyphiidae

Region for assessment:

  • Global
Figure(s) or Photo(s): 

Fig. 9

Figure 9.  

Troglohyphantes lucifer Isaia, Mammola & Pantini, 2017. Photo credit: Francesco Tomasinelli.

Reviewers

Marc Milne

Paulo Borges

Editor

Pedro Cardoso

Geographic range

Biogeographic realm:

  • Palearctic

Countries:

  • Italy
Map of records (Google Earth): 

Suppl. material 37

Basis of EOO and AOO: Observed

Basis (narrative)

This species was collected in a few localities in the Western Alps. Its low level of subterranean specialisation, together with the high altimetric range found in its known distribution, possibly reflects a higher dispersal capacity when compared to subterranean specialised species. Consequently, it may be possible that the present known range of this species is underestimated. Given this situation, any modelling of the current habitat suitability is unreliable.

Min Elevation/Depth (m): 410
Max Elevation/Depth (m): 1777

Range description

This species occurs both in hypogean and epigean localities in the alpine districts of Northern Cottian and Southern Graian Alps (Piemonte, north-western Italy) (detailed occurrences and relative references in Suppl. material 67).

Extent of occurrence

EOO (km2): 1176
Trend: Stable

Justification for trend

This species is not strictly relegated to deep subterranean habitats, being collected in the vicinity of the cave entrance or in shallow subterranean habitats. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised Troglohyphantes (Mammola et al. 2019a), the distribution range of T. lucifer is not expected to undergo significant reduction in the near future. A deeper study on the current distribution of this species and on the potential impacts of climate change is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Area of occupancy

AOO (km2): 40
Trend: Stable

Justification for trend

This species is not strictly relegated to deep subterranean habitats, being collected in the vicinity of the cave entrance or in shallow subterranean habitats. It is plausible that anthropogenic climate change may affect the habitat suitability of this species. However, in view of the relatively wide thermal tolerance and the relatively high dispersal ability of non-specialised Troglohyphantes (Mammola et al. 2019a), the distribution range of T. lucifer is not expected to undergo significant reduction in the near future. A deeper study on the current distribution of this species and on the potential impacts of climate change is required.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Locations

Number of locations: Not applicable

Justification for number of locations

No known threats to this species.

Trend: Stable

Population

Number of individuals: Unknown
Trend: Stable

Justification for trend

There are no currently known threats to this species.

Causes ceased?: Yes
Causes understood?: Yes
Causes reversible?: Yes

Subpopulations

Number of subpopulations: Unknown
Trend: Unknown

Habitat

System: Terrestrial
Habitat specialist: No

Habitat (narrative)

Troglohyphantes lucifer has been collected in floors and walls of the twilight zone of natural caves, in block fields in beech forests, and in various shallow subterranean habitats, leaf litter, deep soil strata, MSS, and rocky accumulations. According to Isaia et al. (2017), in certain localities T. lucifer is able to coexist with other Troglohyphantes spiders. In this regard, Deeleman-Reinhold (1978) suggested that the co-occurrence of more species of Troglohyphantes is rare and may occur exclusively in phylogenetically distant lineages.

Trend in extent, area or quality?: Unknown
Habitat importance: Major Importance
Habitats: 
  • 1.4. Forest - Temperate
  • 6. Rocky areas (e.g. inland cliffs, mountain peaks)
  • 7. Caves and Subterranean Habitats (non-aquatic)

Ecology

Size: 3.5 mm
Generation length (yr): 2
Dependency of single sp?: No

Ecology and traits (narrative)

This species is not exclusively restricted to deep subterranean habitats, being collected in the vicinity of the cave entrance or in shallow subterranean habitats. Specimens show minor morphological specialisation to subterranean life, with eyes normally developed and abdominal pattern present (Mammola et al. 2022a). According to thermal tests, T. lucifer shows a great thermal tolerance, reaching 50% mortality at temperature values 19°C above its cave temperature (Mammola et al. 2019a).

Threats

Threat type: Past
Threats:
  • 12. Other options - Other threat

Justification for threats

The existence of threats is unknown for this species.