Species conservation profiles of a random sample of world spiders IV: Scytodidae to Zoropsidae

Abstract Background The IUCN Red List of Threatened Species is the most widely used information source on the extinction risk of species. One of the uses of the Red List is to evaluate and monitor the state of biodiversity and a possible approach for this purpose is the Red List Index (RLI). For many taxa, mainly hyperdiverse groups, it is not possible within available resources to assess all known species. In such cases, a random sample of species might be selected for assessment and the results derived from it extrapolated for the entire group - the Sampled Red List Index (SRLI). The current contribution is the final in four papers that will constitute the baseline of a future spider SRLI encompassing 200 species distributed across the world. New information A sample of 200 species of spiders were randomly selected from the World Spider Catalogue, an updated global database containing all recognised species names for the group. The selected species were classified taxonomically at the family level and the familes were ordered alphabetically. In this publication, we present the conservation profiles of 50 species belonging to the families alphabetically arranged between Scytodidae and Zoropsidae, which encompassed Scytodidae, Selenopidae, Sicariidae, Sparassidae, Tetrablemmidae, Tetragnathidae, Theraphosidae, Theridiidae, Theridiosomatidae, Thomisidae, Trochanteriidae, Zodariidae and Zoropsidae.


Introduction
The IUCN Red List of Threatened Species is the most widely used information source on the extinction risk of species (Lamoreux et al. 2003, Rodrigues et al. 2006 but see Cardoso et al. 2011b, Cardoso et al. 2012. It is based on a number of objective criteria, which are relatively easy to apply when adequate information is available (IUCN 2001). The Red List has been used to raise awareness about threatened species, guide conservation efforts and funding, set priorities for protection, measure site irreplaceability and vulnerability and influence environmental policies and legislation (Gardenfors et al. 2001, Rodrigues et al. 2006, Martin-Lopez et al. 2009).
One of the uses of the Red List is to evaluate and monitor the state of biodiversity and a possible approach for this purpose is the Red List Index (RLI). The RLI helps to develop a better understanding of which taxa, regions or ecosystems are declining or improving their conservation status. It provides policy-makers, stakeholders, conservation practitioners and the general public with sound knowledge of biodiversity status and change and tools to make informed decisions. The RLI uses weight scores based on the Red List status of each of the assessed species. These scores range from 0 (Least Concern) to 5 (Extinct/ Extinct in the Wild). Summing these scores across all species, relating them to the worstcase scenario -all species extinct and comparing two or more points in time, gives us an indication of how biodiversity is doing. At a global level, the RLI has been calculated for birds (Butchart et al. 2004, Hoffmann et al. 2010, mammals (Hoffmann et al. 2011), amphibians (Hoffmann et al. 2010), corals ) and cycads (United Nations 2015).
For many taxa, mainly hyperdiverse groups, it is not possible within available resources to assess all known species. In such cases, a random sample of species might be selected for assessment and the results derived from it extrapolated to the entire group -the Sampled Red List Index (SRLI, Baillie et al. 2008). The SRLI is now being developed for plants (Brummitt et al. 2015) and efforts towards a SRLI of butterflies (Lewis and Senior 2010) and Odonata are also in progress (Clausnitzer et al. 2009).
Spiders currently comprise over 47000 species described at the global level (World Spider Catalog 2018). Of these, only 200 species (0.4%) have been assessed (www.redlist.org), of which the vast majority are from the Seychelles Islands or belong to the golden-orb weavers, Nephilidae. To these, a large number will be added in the near future, such as 55 species endemic to the Madeira and Selvagens archipelagos and 25 endemic to the Azores, all in Portugal (Cardoso et al. 2017, Borges et al. submitted). The vast majority of spiders assessed to date are therefore either regionally or taxonomically clustered and do not represent the group as a whole. The current contribution is the final in four papers (Seppälä et al. 2018a, Seppälä et al. 2018b, Seppälä et al. 2018c) that constitute the baseline of a future spider SRLI encompassing 200 species distributed across the world. All the assessments will, in the future, be included in the IUCN Red List of Threatened Species (www.redlist.org).

Methods
A sample of 200 species of spiders were randomly selected from the World Spider Catalog (2018), an updated global database containing all recognised species names for the group. The 200 selected species were divided taxonomically to the family level and those families were ordered alphabetically. In this publication, we present the conservation profiles of 58 species belonging to the families alphabetically arranged between Scytodidae and Zoropsidae, which encompassed Scytodidae, Selenopidae, Sicariidae, Sparassidae, Tetrablemmidae, Tetragnathidae, Theraphosidae, Theridiidae, Theridiosomatidae, Thomisidae, Trochanteriidae, Zodariidae and Zoropsidae.
For all analyses, we used the R package 'red' -IUCN red-listing tools (Cardoso 2017). This package performs a number of spatial analyses based on either observed occurrences or estimated ranges. Functions include calculating Extent of Occurrence (EOO), Area of Occupancy (AOO), mapping species ranges, species distribution modelling using climate and land cover, calculating the Red List Index for groups of species, amongst others. In this work, the EOO and AOO were calculated in one of two ways: -For extremely range-restricted species for which we assumed to know the full range, these values were classified as observed, the minimum convex polygon encompassing all observations used to calculate the EOO and the 2 km x 2 km cells known to be occupied were used to calculate the AOO. When the EOO was smaller than the AOO, it was made equal as per the IUCN guidelines (IUCN Standards and Petitions Subcommittee 2017).
-For widespread species or those for which we did not have confidence to know the full range, we performed species distribution modelling (SDM). This was done based on both climatic (Fick and Hijmans 2017) and landcover (Tuanmu and Jetz 2014) datasets, at an approximately 1 x 1 km resolution. Before modelling, the world layers were cropped to the region of interest to each species and reduced to four layers through a PCA to avoid overfitting. In addition, latitude and longitude were used as two extra layers to prevent the models from predicting presences far beyond the known region following the precautionary principle. We then used the Maxent method (Phillips et al. 2006) implemented in the R package 'red'. Isolated patches outside the original distribution polygon were excluded from maps to avoid overestimation of EOO and AOO values. All final maps and values were checked and validated by the authors. KMLs derived from these maps were also produced using the red package. The cells (2x2 km), predicted to be occupied, were used to calculate the AOO. When the EOO was smaller than the AOO, it was made equal as per the IUCN guidelines (IUCN Standards and Petitions Subcommittee 2017).
To infer possible changes in range and/or abundance and for forest species only, we also consulted the Global Forest Watch portal (World Resources Institute 2014), looking for changes in forest cover during the last 10 years that could have affected the species.
Species sizes are total body size in mm and include the ranges for both males and females when known. and nocturnal hunters that have specialised prey catching techniques. These spiders are also the only ones that are known to have prosomal glands that secrete not only venom but also silk. Scytodids are able to squirt a mixture of venom and gluey silk towards its prey which then gets stuck in the substrate, the venom causing a paralysis. The female lays eggs in a silken retreat and the eggs are carried in the chelicerae and pulled together with a couple of silk threads (Dippenaar-Schoeman and Jocqué 1997).

Habitat (narrative):
This species thrives in arid, desert-like habitats in Texas and Mexico (Gertsch 1958, Gertsch and Ennik 1983, GBIF.org 2018b commonly living under rocks, in caves, shrubland, sand dunes and occasionally in artificial habitats such as palm groves and road cuts (Gertsch and Mulaik 1940, Gertsch 1958, Gertsch and Ennik 1983, GBIF.org 2018b. Trend in extent, area or quality?: Increase Justification for trend: It preferred habitat, desert-like arid, is increasing in extent (United States Department of Agriculture 2003).

Ecology and traits (narrative)
The spiders of the genus Loxosceles are nocturnal ground-dwelling hunters that live under stones and other ground objects. Loxoscelids build a retreat with irregular webs. The webs of these species have been described as white, adhesive and flocculent. Many species in this genus have been reported to have strong venom since the haematoxins in the venom of Loxosceles destroys the cells of the skin after biting often resulting in necrosis (Gertsch 1958).

Threat type: Ongoing
Threats: -12. Other options -Other threat Justification for threats: No known threats.

System: Terrestrial
Habitat specialist: Unknown

Habitat (narrative)
Isopeda seems to be present only in areas with rainfall above 500 mm. One of the records was reported from Hardings swamp (Hirst 1992).

Trend in extent, area or quality?: Decline (inferred)
Justification for trend: There is decline in habitat quality as there has been reported decline in the rainfall and increase in the daily maximum temperature (Murphy and Timbal 2008).

Ecology and traits (narrative)
Males of I. echuca have been observed from August to June, although it has been suggested both males and females may be present throughout the year and the existing gaps may be due to insufficient sampling and inactivity of the spiders (Hirst 1992). Spiders of the family Sparassidae in general are nocturnal and wandering hunters living on the soil surface or on plants (Jocqué and Dippenaar-Schoeman 2006).

Threat type: Ongoing
Threats: -11.2. Climate change & severe weather -Droughts Justification for threats: Since this species seems to prefer moist habitats, the ongoing climate change is affecting the habitat quality as there has been reported decline in the rainfall and daily maximum temperatures are rising (Murphy and Timbal 2008).

Justification for research needed:
Monitoring is needed to confirm population and habitat trends and also conservation planning could take place given the continuing decline in habitat quality.

Dependency of single sp?: Unknown
Ecology and traits (narrative): This is a pale-coloured species whose single specimen was found from a cave in limestone (Jäger 2012

Ecology and traits (narrative)
Members of the family Tetrablemmidae are small to tiny spiders known as "armored spiders" due to their heavily scleritised bodies. These three-clawed, ecribellate, haplogyne spiders are covered with a hardened shell or abdominal scutae (ventral, dorsal and lateral) hinged with softer material allowing expansion between the plates in a bellows-like way (Lehtinen 1981;Labarque and Grismado 2009;Whyte and Anderson 2017). They are typically found in tropical and semitropical habitats, although a species of Shearella has been found living in dry coastal habitats (Lehtinen 1981). Very little is known about their behaviour although Burger et al. (2006) recorded the first observation of tetrablemmid spiders mating in Thailand and the web and egg-sac construction of Brignoliella vulgaris have been observed (Lehtinen 1981). Tetrablemmid spiders have been collected from moss and leaf litter; under stones, bark or logs; in soil samples including hanging soils such as in orchids and epiphytes as well as in dark caves (Tong and Li 2008). Some cave and soil dwelling species have reduced number of eyes such as in the genus Tetrablemma which have only four (Whyte and Anderson 2017). The cave dwelling species Tetrablemma brevidens is part of the first report of tetrablemmid spiders recorded from China found on Hainan Island by Tong and Li (2008).

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: Unknown threats.

Range description
This species is present in Costa Rica and Panama. According to Dimitrov and Hormiga (2009a), the genus Cyrtognatha is widespread in South America, Central America and the southern parts of North America, although the majority of the species are known from single localities. The latest known record is from 1995, from La Amistad International Park in Panama (Dimitrov and Hormiga 2009a). Since there are only few data from a limited number of localities on this species, its range might be relatively narrow as predicted by the

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Unknown
Basis (narrative): EOO and AOO are unknown.

Max Elevation/Depth (m): 820
Range description: Known only from the type locality in Barberton, Transvaal, South Africa, recorded once in 1897 (Purcell 1903).

System: Terrestrial
Habitat specialist: Unknown

Habitat (narrative):
There is no recorded habitat data available. The type locality falls into the ecoregion of tropical and subtropical grasslands, savannahs and shrublands (Olson et al. 2001).

Trend in extent, area or quality?: Unknown
Habitat importance: Major Importance Ecology and traits (narrative): Spiders of the family Theraphosidae are free-living, ground-dwelling spiders. They build a burrow lined with silk or hide in a retreat under a rock (Jocqué and Dippenaar-Schoeman 2006). Theraphosid males do not moult when they reach maturity and they also have a shorter lifespan compared to females (Costa and Pérez-Miles 2002). Burrows often have their own two chambers: one is for the spider to moult and the other to eat and rest (Locht et al. 1999).

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: Unknown threats.

Other
Use type: International

Region for assessment:
-Global

Geographic range
Biogeographic realm:

-Mexico
Map of records (Google Earth): Suppl. material 14

Basis of EOO and AOO: Unknown
Basis (narrative): Unknown EOO and AOO.

Max Elevation/Depth (m): 1960
Range description: This species has been recorded only once from unspecified locality in Mexico prior to 1999(Vol 1999. Although the geographical origin of this species is not mentioned in the bibliography, this genus has been broadly trafficked for the pet trade from Mexico into Europe and Northern America (the type specimen itself was reared in captivity). Only known to the scientific world from a single female moult, this monogeneric genus appears to hold several undescribed species, which have not yet been scientifically analysed and whose range cannot be mapped. It is therefore impossible at this stage in our knowledge to assess the distribution range of this particular species, although the fact that it has not been scientifically analysed but appears in the pet trade might indicate it does not inhabit remote localities but is rather highly localised. It is possibly threatened with deforestation and illegal trade.

Dependency of single sp?: Unknown
Ecology and traits (narrative): Spiders of the family Theraphosidae are free-living, ground-dwelling spiders. They build a burrow lined with silk or hide in a retreat under a rock (Jocqué and Dippenaar-Schoeman 2006). Theraphosid males do not moult when they reach maturity and they also have shorter lifespans compared to females (Costa and Pérez-Miles 2002). The burrow might have two chambers: one is for the spider to moult and the other to eat and rest (Locht et al. 1999).

Threats
Threat type: Ongoing Threats: -5.1.1. Biological resource use -Hunting & trapping terrestrial animals -Intentional use (species is the target) Justification for threats: This genus has been broadly trafficked for the pet trade from Mexico into Europe and Northern America and therefore collection as a pet may be a threat to this particular species as well.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

-Indomalayan
Countries: -Viet Nam Ecology and traits (narrative): Spiders of the family Theraphosidae are free-living, ground-dwelling spiders. They build a burrow lined with silk or hide in a retreat under a rock (Jocqué and Dippenaar-Schoeman 2006). Theraphosid males do not moult when they reach maturity and they also have a shorter lifespan compared to females (Costa and Pérez-Miles 2002).

Threat type: Ongoing
Threats: -5.1.1. Biological resource use -Hunting & trapping terrestrial animals -Intentional use (species is the target) Justification for threats: Collection of individuals from the wild to feed the pet market may be a threat to this species.

Conservation action type: Needed
Conservation actions:

. Education & awareness -Awareness & communications
Justification for conservation actions: It would be essential to raise awareness and communication of the consequences of the pet trade on exotic animals.

Use type: International
Use and trade: -13. Pets/display animals, horticulture

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis (narrative):
Only three records (Ferretti and Barneche 2012) make it impossible to assess the true distribution of the species.

Max Elevation/Depth (m): 120
Range description: This species is known only from Chaco province, Argentina, found and recorded in 2012 (Ferretti and Barneche 2012).

Trend: Unknown
Justification for trend E. larae is capable of inhabiting even modified areas with human disturbance (Ferretti and Barneche 2012) which may suggest the EOO of this species is probably not experiencing any decline. Yet, this is very uncertain.

Trend in extent, area or quality?: Stable
Justification for trend: This species tolerance to human disturbance can be advantageous to its survival.

Habitat importance: Major Importance
Habitats:

Ecology and traits (narrative)
Spiders of the family Theraphosidae are free-living, ground-dwelling spiders. They build a burrow lined with silk or hide in a retreat under a rock (Jocqué and Dippenaar-Schoeman 2006). Theraphosid males do not moult when they reach maturity and they also have a shorter lifespan compared to females (Costa and Pérez-Miles 2002). E. larae is active at night and come outside their burrow to wait for a prey. Burrows can be deep and temperature inside it can be almost 10ºC cooler compared to the outside temperature. The population density can be high with many specimens within a few square metres (Ferretti and Barneche 2012).

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: No known threats.

Conservation action type: In Place
Other

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Max Elevation/Depth (m): 0
Range description: This species has been recorded only once from an unconfirmed type locality prior to 1917 (Chamberlin 1917). The description paper sets the type locality as Tortugas in Florida and therefore the type locality here is considered as Dry Tortugas National Park. However, Rudloff (2008) suggested this locality would be more likely Tortuga Island in Hispaniola (Cuba). Hence, the known distribution of this species remains unconfirmed.

Dependency of single sp?: No
Ecology and traits (narrative): Spiders of the family Theraphosidae are free-living, ground-dwelling spiders. They build a burrow lined with silk or hide in a retreat under a rock (Jocqué and Dippenaar-Schoeman 2006). Theraphosid males do not moult when they reach maturity and they also have a shorter lifespan compared to females (Costa and Pérez-Miles 2002).

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: Unknown threats.

Conservation action type: In Place
Other

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Unknown
Basis (narrative): Unknown EOO or AOO.

Min Elevation/Depth (m): 90
Max Elevation/Depth (m): 120 Range description: Known only from two localities, from Soriano in Uruguay, recorded prior to 1901 (Pocock 1901) and from Rio Grande do Sul in Brazil, recorded prior to 1923(Mello-Leitão 1923.

Ecology and traits (narrative)
Spiders of the family Theraphosidae are free-living, ground-dwelling spiders. They build a burrow lined with silk or hide in a retreat under a rock (Jocqué and Dippenaar-Schoeman 2006). Theraphosid males do not moult when they reach maturity and they also have a shorter lifespan compared to females. Plesiopelma species line their burrows with silk. One species from the same genus, Plesiopelma longisternale, was captured by pitfall traps in Uruguay (particularly in Sierra de las Animas, Maldonado and Quebrada de los Cuervos, Treinta y Tres) (Costa and Pérez-Miles 2002).  observed that both females and juveniles of Plesiopelma longisternale were absent during a same seasonal period and were found from pitfall traps. Males have been collected at least from April to December. Females were found carrying egg-sacs during December and January in the field and the sacs were reported to contain over 100 eggs. P. longisternale females were reported to live over 4 years in the laboratory and moulted every 1.5 years, usually in spring (Costa and Pérez-Miles 2002).

Threats
Threat type: Past

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Species Distribution Model
Basis (narrative): Given the relatively high number of records (Pocock 1895, Samarawckrama et al. 2005, Benjamin et al. 2012, Gabriel 2013, it was possible to perform species distribution modelling (see methods for details).

Max Elevation/Depth (m): 2410
Range description: This species is endemic to Sri Lanka and restricted to its central parts, last recorded in the wild in the 1990s but many pet records are from 2000s (Pocock 1895, Samarawckrama et al. 2005, Benjamin et al. 2012, Gabriel 2013.

Ecology and traits (narrative)
Species of Poecilotheria are tree-dwellers, where they spin small webs in the bifurcations of branches. Given their large size, they might feed on small vertebrates besides the regular large invertebrate diet.

Threats
Threat type: Ongoing

Taxonomic notes
L. convexa has been transferred between the genera Dipoena and Lasaeola for several times (e.g. Wunderlich 2011, Le Peru 2011, IJland et al. 2012) and therefore further taxonomic clarification would be needed.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Ecology and traits (narrative)
Ecology of this particular species is largely unknown. Contrary to most theridiids, Lasaeola do not build webs and feed almost exclusively on ants at ground level, on low bushes or on the bark of trees. Females occur from January to June and also in November, while males are seen in spring and in October (Le Peru 2011).

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: No known threats to the species.

System: Terrestrial
Habitat specialist: Yes

Habitat (narrative)
This species was found only in Pisonia forest and spins its webs in vegetation (Saaristo 2006).

Justification for trend
Although the habitat has been deteriorating due to the effects of invasive plant species, Sesato setosa appears to dwell in areas around the local village, hence it is unknown if the species is being affected.

Habitat importance: Major Importance
Habitats: -1.6. Forest -Subtropical/Tropical Moist Lowland  (Saaristo 2006). Otherwise, the ecology of this particular species is largely unknown. Theridiids in general build space webs which are irregular in shape; threads are often configured in different directions (Jocqué and Dippenaar-Schoeman 2006). These threads tend to break easily when capturing prey. These glue-bearing threads make it difficult for prey to flee and easy for a spider to capture them.

Justification for threats
This species habitat is threatened due to the effects of invasive plants, especially Cinnamomum verum. Yet, we do not know if it affects the spider.

Conservation action type: In Place
Conservation actions: -1.1. Land/water protection -Site/area protection

Conservation action type: Needed
Conservation actions: -2.1. Land/water management -Site/area management -2.2. Land/water management -Invasive/problematic species control Justification for conservation actions: This species is found in the Silhouette National Park, yet the park is not currently managed. Invasive species were managed on Silhouette until 2010 but any actions have been abandoned since. If the spider is in any way affected by invasive plant species, it may be essential to its survival to take consider invasive species management as a possible action.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

-Israel
Map of records (Google Earth): Suppl. material 23

Basis of EOO and AOO: Unknown
Basis (narrative): Very few records in Israel (Levy andAmitai 1982, Levy 1998) do not allow knowing the true range of the species.

Max Elevation/Depth (m): 660
Range description: This species has been recorded for the Negev, a desertic and semidesertic region of southern Israel, recorded in 1973 (Levy and Amitai 1982).

Causes ceased?: Unknown
Ecology and traits (narrative): Ecology of this particular species is largely unknown. Theridiids in general build space webs which are irregular in shape; threads are often configured in different directions (Jocqué and Dippenaar-Schoeman 2006). These threads tend to break easily when capturing prey. These glue-bearing threads make it difficult for prey to flee and easy for a spider to capture them.  , Song et al. 1999, Yoshida et al. 2000, Yin et al. 2012, it was possible to perform species distribution modelling (see methods for details).

Max Elevation/Depth (m): 1830
Range description: Recorded from several sites in China between the 1980s and 1990s (Zhu and Song 1992, Song and Li 1997, Song et al. 1999, Yoshida et al. 2000, Yin et al. 2012). The last known record is from Orchid Island, Taiwan (Yoshida et al. 2000). This species is predicted to also occur in Myanmar.

EOO (km2): 1719562
Trend: Stable Justification for trend: As it is a widespread species with no specific habitat requirements or known threats, we assume the trend to be stable.

AOO (km2): 515972
Trend: Stable Justification for trend: As it is a widespread species with no specific habitat requirements or known threats, we assume the trend to be stable.

Number of locations: Not applicable
Justification for number of locations: No known threats to the species.

Number of individuals: Unknown
Trend: Stable Justification for trend: As it is a widespread species with no specific habitat requirements or known threats, we assume the trend to be stable.

Causes reversible?: Yes
Population Information (Narrative): No population size estimates exist. This species is widespread in South East Asia.

Trend: Stable
Justification for trend: As it is a widespread species with no specific habitat requirements or known threats we assume the trend to be stable.

System: Terrestrial
Habitat specialist: Unknown Habitat ( Ecology and traits (narrative): Ecology of this particular species is largely unknown. Theridiids in general build space webs which are irregular in shape; threads are often configured in different directions (Jocqué and Dippenaar-Schoeman 2006). These threads tend to break easily when capturing prey. These glue-bearing threads make it difficult for prey to flee and easy for a spider to capture them.

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: No known threats.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis (narrative):
Given the relatively high number of records (Gertsch and Archer 1942, Schenkel 1950, Levi 1957, it was possible to perform species distribution modelling (see methods for details).

Max Elevation/Depth (m): 1060
Range description: This species is known from several sites from the west coast of the USA (Gertsch and Archer 1942, Schenkel 1950, Levi 1957, last recorded prior to 1957 (Levi 1957). In addition, the SDM predicts suitable habitat to be present in Mexico (Baja California) and Canada (British Columbia) as well.

Habitat (narrative):
The habitat of this species is unknown. One specimen was found from tree bark (Levi 1957).

Trend in extent, area or quality?: Unknown
Habitat importance: Major Importance

Dependency of single sp?: No
Ecology and traits (narrative): Ecology of this particular species is largely unknown. Theridiids in general build space webs which are irregular in shape; threads are often configured in different directions (Jocqué and Dippenaar-Schoeman 2006). These threads tend to break easily when capturing prey. These glue-bearing threads make it difficult for prey to flee and easy for a spider to capture them.

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: Unknown threats.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Unknown
Basis (narrative): Unknown EOO or AOO.

Max Elevation/Depth (m): 20
Range description: Known only from the type locality in Santa Cruz, Veracruz, Mexico, recorded once prior to 1959 (Levi 1959). There are many places named Santa Cruz within the Veracruz region in Mexico, hence the coordinates for Veracruz are presented on the map.

Dependency of single sp?: Unknown
Ecology and traits (narrative): Ecology of this particular species is unknown. Theridiids in general build space webs which are irregular in shape; threads are often configured in different directions (Jocqué and Dippenaar-Schoeman 2006). These threads tend to break easily when capturing prey. These glue-bearing threads make it difficult for prey to flee and easy for a spider to capture them.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

-Neotropical
Countries: -Saint Vincent and the Grenadines

Basis of EOO and AOO: Unknown
Basis (narrative): Unknown EOO or AOO.

Range description
Simon (1897) did not specify a locality for the holotype of Ogulnius infumatus except for the island of Saint Vincent in the Caribbean. The species has not been reported since.

Habitat (narrative):
The habitat of this particular species is unknown. Theridiosomatids in general have been observed to prefer wet and humid habitats, for example dark forests and some have been recorded from caves as well (Coddington 1986).

Trend in extent, area or quality?: Unknown
Habitat importance: Major Importance

Dependency of single sp?: No
Ecology and traits (narrative): Ecology of this species is largely unknown. Theridiosomatids in general tend to build a web that varies in shape (complete orb webs to networks with a few threads) and some species do not build a web at all. Webs are often built in litter or in low vegetation (Coddington 1986, Dippenaar-Schoeman andJocqué 1997).

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: Unknown threats.

Use type: International
Use and trade: -18. Unknown

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Unknown
Basis (narrative): Unknown EOO or AOO.

Max Elevation/Depth (m): 120
Range description: The species is only known from the type locality, from a single collection dated over 130 years ago (Keyserling 1884).

Dependency of single sp?: No
Ecology and traits (narrative): Ecology of this species is largely unknown. Theridiosomatids in general tend to build a web that varies in shape (complete orb webs to networks with a few threads) and some species do not build a web at all. Webs are often built in litter or in low vegetation (Coddington 1986, Dippenaar-Schoeman andJocqué 1997).

Threats
Threat type: Ongoing

Conservation action type: Needed
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 collected in an area of tropical rainforest that has been partially deforested (Global Forest Watch 2014). This area of tropical rainforest has also been shown to have been affected by fire, likely set by nearby human populations to aid in deforestation (Bachman et al. 2011). Although the population values are unknown, it is likely that drastic deforestation and fire in this species habitat would be detrimental to its survival and increase its extinction risk. It is therefore recommended that deforestation and fire in this habitat be carefully managed.

Use type: International
Use and trade: -18. Unknown

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Unknown
Basis (narrative): Unknown EOO or AOO.

EOO (km2): Unknown
Trend: Unknown Ecology and traits (narrative): Ecology of this species is unknown. Thomisids in general are ambush predators and do not build webs. Also known as crab spiders, they are most active during the day and usually wear a cryptic colour which help them to camouflage and wait for their prey, for example, by sitting on a plant. With their acute vision, they detect the prey and then attack. The prey are sometimes over twice the size of the spider and are paralysed with strong venom (Dippenaar-Schoeman and Jocqué 1997).

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: Unknown threats.

Use type: International
Use and trade: -18. Unknown

Ecology and traits (narrative)
Ecology of this species is unknown. Thomisids in general are ambush predators and do not build webs. Also known as crab spiders, they are most active during the day and usually wear a cryptic colour which help them to camouflage and wait for their prey, for example, by sitting on a plant. With their acute vision, they detect the prey and then attack. The prey are sometimes over twice the size of the spider and are paralysed with strong venom (Dippenaar-Schoeman and Jocqué 1997). Epicadus species are medium-sized spiders with a remarkable sexual size dimorphism, commonly found on leaves or flowers (Silva-Moreira and Machado 2016). According to Machado et al. (2017), the genus Epicadus is included in a clade of spiders that display a variety of polychromatism and use flowers to hunt.

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: No known threats.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

-Cuba
Map of records (Google Earth): Suppl. material 32 wear a cryptic colour which help them to camouflage and wait for their prey, for example, by sitting on a plant. With their acute vision, they detect the prey and then attack. The prey are sometimes over twice the size of the spider and are paralysed with strong venom (Dippenaar-Schoeman and Jocqué 1997).

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: Unknown threats.

Use type: International
Use and trade: -18. Unknown

Ecosystem service type: Very important
Research needed:

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

Dependency of single sp?: No
Ecology and traits (narrative): Ecology of this species is unknown. Thomisids in general are ambush predators and do not build webs. Also known as crab spiders, they are most active during the day and usually wear a cryptic colour which help them to camouflage and wait for their prey, for example, by sitting on a plant. With their acute vision, they detect the prey and then attack. The prey are sometimes over twice the size of the spider and are paralysed with strong venom (Dippenaar-Schoeman and Jocqué 1997).

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis (narrative):
Although there were few records (Tikader 1980, Sen et al. 2015, it was possible to perform species distribution modeling (see methods for details).

Max Elevation/Depth (m): 1770
Range description: This species is known from three sites in India; it was recorded in 1971 from Andmana Islands and in 2009 from Kalijhora and Budhuram (Tikader 1980, Sen et al. 2015. However, the species distribution model predicts the existence of suitable habitat in neighbouring regions and countries.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

EOO (km2): 11568241
Trend: Stable Justification for trend: As it is a widespread species with no known threats, the trend is assumed to be stable.

AOO (km2): 10103920
Trend: Stable Justification for trend: As it is a widespread species with no known threats, the trend is assumed to be stable.  (Kaston 1948). Thomisids in general are ambush predators and do not build webs. Also known as crab spiders, they are most active during the day and usually wear a cryptic colour which help them to camouflage and wait for their prey, for example, by sitting on a plant. With their acute vision, they detect the prey and then attack. The prey are sometimes over twice the size of the spider and are paralysed with strong venom (Dippenaar-Schoeman and Jocqué 1997). Species of this genus are dark in colour and inhabit the leaf litter, bark of trees and open areas (Dippenaar-Schoeman and Jocqué 1997, Paquin et al. 2008.

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: No known threats.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Unknown
Basis (narrative): Unknown EOO or AOO.

Max Elevation/Depth (m): 60
Range description: Known only from the type locality in Roro (Yule Island). The species is only mentioned in its original taxonomical description (Thorell 1881) and has not been recorded for over 135 years. But despite the long period with no observations and the reduced size of the island where the species was found (13 km2), it is only 2 km away from the mainland at its nearest point and very few arachnological surveys have ever been conducted in the country, none in the region close to Yule Island. Therefore the fact that it has not been found for so long can be easily due to the lack of prospecting.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Dependency of single sp?: Unknown
Ecology and traits (narrative): Thomisids in general are ambush predators and do not build webs. Also known as crab spiders, they are most active during the day and usually wear a cryptic colour which help them to camouflage and wait for their prey, for example, by sitting on a plant. With their acute vision, they detect the prey and then attack. The prey are sometimes over twice the size of the spider and are paralysed with strong venom (Dippenaar-Schoeman and Jocqué 1997).

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: Unknown threats.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Basis of EOO and AOO: Unknown
Basis (narrative): Unknown EOO or AOO.

Max Elevation/Depth (m): 1430
Range description: Known only from the type locality in Central Africa, specifically at Kiwu Lake in Rwanda, recorded in 1907(Strand 1913. No records have been published after species description, which may be due to insufficient exploration.

Ecology and traits (narrative)
Thomisids in general are ambush predators and do not build webs. Also known as crab spiders, they are most active during the day and usually wear a cryptic colour which help them to camouflage and wait for their prey, for example, by sitting on a plant. With their acute vision, they detect the prey and then attack. The prey are sometimes over twice the size of the spider and are paralysed with strong venom (Dippenaar-Schoeman and Jocqué 1997). Species of Xysticus are relatively dark in colour and instead of flowers they hunt on the leaf litter, bark of trees and open areas (Dippenaar-Schoeman and Jocqué 1997, Paquin et al. 2008. According to Levy (1976), the males and females of this particular species are both present in April and May, females occurring until August. Several unmated females have been reported to lay unfertilised eggs when in the laboratory (Levy 1976).

Threat type: Past
Threats: -12. Other options -Other threat Justification for threats: No known threats.

Region for assessment:
-Global

Geographic range
Biogeographic realm:

Map of records (Google Earth): Suppl. material 48
Threats: -7.1.1. Natural system modifications -Fire & fire suppression -Increase in fire frequency/intensity Justification for threats: From 50,000 to over 150,000 fires have been reported between 2012 and 2017 for Western Australia (Global Forest Watch 2014). This may cause a possible threat to the survival of this species, although this is uncertain. Monitoring is needed to confirm the current population and habitat trends. Also more data on the ecology and traits of this species is required to assess its sensitivity to forest fires.

Results
A total of 200 species have been assessed within this project (Seppälä et al. 2018a, Seppälä et al. 2018b, Seppälä et al. 2018c, belonging to 47 of the currently recognised 118 families ( Fig. 1; World Spider Catalog 2018). As expected by a random sample, our study species follow the known species richness per family, with the most represented being the jumping spiders (Salticidae, 31 species), orb-weavers (Araneidae, 18 species), crab spiders (Thomisidae, 16 species), wolf spiders (Lycosidae, 15 species), ground spiders (Gnaphosidae, 11 species) and sheet weavers or money spiders (Linyphiidae, 11 species). These broadly correspond to the families with more described species to date (World Spider Catalog 2018). All other families in our sample were represented by less than 10 species.
The Neotropics (54 species) and the Palearctic (47 species) were the most represented biogeographical realms (Fig. 1). The Oceanian realm (with only 2 species) and the Antarctic (no species) were scarcely or not represented. This is probably due as much to lack of knowledge as to low species richness in some regions.
Nephilingis cruentata (Fabricius, 1775) (Nephilidae), Tiso aestivus (L. Koch, 1872) (Linyphiidae) and Ceratinella brunnea Emerton, 1882 (Linyphiidae) were the most widespread species, all with an estimated EOO above 30 million km or AOO above 20   Hewitt, 1916 (Idiopidae, from South Africa) was driven to extinction during the 20th century. Of these, we could find evidence of decline in EOO or AOO for all species but S. setosa. C. bolganupensis, Z. mulanjensis and G. robertsi were under severe threat from habitat destruction from wildfires, deforestation and urbanisation, respectively. For 118 of the species in our study, it was not possible to estimate the Extent of Occurrence or Area of Occupancy due to the scarcity of reliable data (Fig. 2). The trends in EOO and AOO were assumed to be stable for 50 out of the 59 species with some data available, although there is no monitoring data for any taxon. Only for nine species we found evidence of decline mainly due to habitat loss or degradation (Fig. 2).
Data on habitat was available for 119 of the studied species (Fig. 3). Forest was the most common habitat type (66 species), followed by grasslands (24 species). For 47 species the habitat quality trend was inferred to be stable, only declining for 15 and increasing for 1 species. For the remaining 137 species, the habitat quality trend could not be inferred and was thus classified as unknown (Fig. 3). The most common threat types amongst the 31 species for which threat data were available (Fig. 4) were agriculture (11 species), wildfires (9 species) and logging (8 species). In the case of 36 species, there were no known threats to the species, mostly amongst the widespread and well-known taxa. For 133 species, the available information was not sufficient to attribute the existence of any specific kind of threat (Fig. 4).
Many species are known to occur within protected areas or habitats and, therefore, the status of the area itself is the most common conservation action currently in place (Fig. 5), even if, for half the taxa, we had no knowledge of their occurrence in PAs or any other protection measure. However, occurrence within protected areas may not be enough for species survival and a number of other conservation actions were suggested, the most common of which being habitat protection, restoration and management, besides a strong emphasis in education and awareness (Fig. 5).
Finally, we identified a number of research priorities for the future (Fig. 6), the most important of which being to better know the species distribution (the Wallacean shortfall; Lomolino 2004), threats and life history and ecology (the Hutchinsonian shortfall; Mokany and Ferrier 2010). Also monitoring of both population (the Prestonian shortfall; Cardoso et al. 2011a) and habitat trends were deemed critical for many species (Fig. 6).

Discussion
This exercise provides a first glimpse into the general trends in the conservation status of spiders around the world. Most notably, this research shows that spider species are most commonly affected by habitat destruction, although climate change, invasive species and direct hunting (for the pet trade) are important threats to some taxa as well. Yet, these threats are for known and assessed species, the vast majority of taxa lacking data on their threats (Cardoso et al. 2011a). Even basic data such as distribution and basic life history are unknown for the great majority of spiders. Unfortunately, without such data, it is impossible to suggest conservation measures to all but a few of the best known species. In the meantime, many of them, including some of the 200 that were assessed herein, may already be extinct. In fact, it is probable that many more species became extinct even before they were described or assessed.
We hypothesise that there should be a higher proportion of threatened species amongst the Data Deficient or undescribed species than amongst those with reasonable information available. This hypothesis is based on two reasons. First, the scarcity of information on many species is often partly due to their rarity. These rare species are harder to collect and hence have a higher probability of remaining undescribed or unrecorded for longer periods or lacking data for their assessment. Exceptions might occur in relatively well-known areas, where rare species are specifically targeted and often better known than common ones. Second, widespread species are often the only ones for which an assessment may be conducted as they are assumed to have stable populations, creating a bias in the dataset towards a large proportion of non-threatened species. This means that a random sample of species, such as the approach followed herein and recognised by the SRLI (Baillie et al. 2008), might not reflect reality. SRLI values reached are probably higher than the real trend and we incur the risk of painting a more optimistic picture than reality. The strategy currently used by the IUCN is therefore inadequate for taxa with scarce information, which represent the vast majority of species within diverse, poorly known groups such as spiders. Hence, we are currently working on a non-random approach for the selection of species for the SRLI (Henriques et al. in prep.).
The Convention on Biological Diversity (CBD) in Aichi, Japan, declared 2010-2020 as the decade of biodiversity. Twenty biodiversity targets were set to be met by the year 2020 (Tittensor et al. 2014). Amongst these, target 12 says "by 2020 the extinction of known threatened species has been prevented and their conservation status, particularly of those most in decline, has been improved and sustained". Yet, if we do not have extinction risk information for the vast majority of species, even if only for the fraction described to date, it is impossible to know how close we are to such a target. This research revealed important information about global trends on the threat status of spider species. However, it also revealed how much we still need to discover to even begin to be able to provide any definitive answers on the threat status of spiders at a global level.