An annotated checklist of millipede fauna from Slovakia, with ecological and biogeographic characteristics

Abstract Background Two decades have passed since the publishing of the last checklist of the millipedes of Slovakia. During this time, several new faunistic records have been added and taxonomic revisions have occurred. The present updated checklist summarises data on all millipede species recorded in Slovakia, including altogether 93 species. New information For each species, general habitat characteristics, ecological classification and distributional pattern are provided. Ecological classification is presented for the first time for the millipede species occurring in Slovakia and is proposed as a tool for ecological studies and for the nature protection purposes. Special remarks are given to the species newly found for Slovakia, Geoglomerissubterranea Verhoeff, 1908, Brachyiuluslusitanus Verhoeff, 1898, Cylindroiulusbritannicus (Verhoeff, 1891), C.parisiorum (Brölemann & Verhoeff, 1896) and Polydesmusburzenlandicus Verhoeff, 1925, as well as to C.arborum Verhoeff, 1928, the species newly confirmed for Slovakia after more than 70 years.


Introduction
Until 1993, Slovakia was part of several political units (Hungarian, Austro-Hungarian Monarchy, Czechoslovakia, Slovak Republic, Hungary); therefore, historical data on Slovak millipede fauna are not easy to find and there has been a lot of geographical confusion in trying to locate old published records. The studies on the millipedes in Slovakia have a long history, with the first papers published at the end of the 19 century (Nowicki 1867, Nowicki 1869, Nowicki 1870, Nowicki 1871, Karliński 1883a, Karliński 1883b, Latzel 1882, Latzel 1884, Chyzer 1886, Daday 1889, Daday 1896, Petricskó 1891, Petricskó 1892, Malesevics 1892, Attems 1895, Attems 1899, Verhoeff 1899a, Verhoeff 1899b. One of the most important authors working at that time in Slovakia was Ödön Tömösváry. He wanted to prepare a monograph on the myriapods of the Kingdom of Hungary, but died young and his findings were at least excerpted in the papers of Chyzer (1886), Daday (1889) and Daday (1896).
In the pre-war and interwar periods, K. W. Verhoeff, the phenomenal German zoologist, expanded the knowledge of the millipedes of our country. In addition, important information about the millipede fauna of Slovakia is included in historical monographs published by Attems (1926), Verhoeff (1928), Verhoeff (1932), Verhoeff (1937), Ortvay (1902) and Schubart (1934). A significant contribution to the knowledge of Slovak millipedes during the first half of the 20 century was done by other authors, including Jawlowski (Jawlowski 1930, Jawlowski 1938, Jermy (1942) and Loksa (Loksa 1954, Loksa 1957, Loksa 1962, Loksa 1968). In the second half of the 20 century, the most extensive research on millipedes in Slovakia was performed by Ján Gulička (1925Gulička ( -2009 (Gulička 1952, Gulička 1954, Gulička 1955, Gulička 1956a, Gulička 1956b, Gulička 1957, Gulička 1960b, Gulička 1965, Gulička 1985, Gulička 1986). Gulička's unpublished compendia (Gulička 1951, Gulička 1960a), which we have today and can work with, were not taken into account in the last published checklist (Mock 2001a). This last checklist included all the available information at that time and involved information for about 70 species reported for the whole territory of Slovakia. A new chapter of millipede research began at the end of the 20 century, conducted by several researchers, for example, Tajovský (1997), Mock (Mock 1998, Mock 1999a, Mock 1999b) and Stašiov (Stašiov 1997, Stašiov 1998. Several studies on Slovak millipede fauna were published after Gulička's death (Gulička 2016, Gulička et al. 2014, Gulička and Košel 2016, based on material and manuscripts from his estate. Besides this, Gulička's unpublished compendia (Gulička 1951, Gulička 1960a), which we have today available and data listed there can be actually re-evaluated and taken th th th th into consideration, represent other sources for more complex overview of the millipede fauna of Slovakia.
Since 2001, the number of species has changed significantly, thus warranting a new update. The aim of this report is to update the list of millipede species and their distribution in Slovakia, to summarise published, as well as unpublished data and records, respecting recent taxonomic changes and to provide a useful tool in the form of ecological and geographical classification of species for other studies.

Materials and methods
The classification for Diplopoda used for this checklist follows the systematic arrangement by Shear (2011), while the nomenclature follows Kime andEnghoff (2011), Kime andEnghoff (2013), Kime and Enghoff (2017). We verified the system and nomenclature using MilliBase (Sierwald and Spelda 2021); however, we are reticent towards some proposals, for example, dividing the genera Brachydesmus and Polydesmus into other genera.
We do not include the subspecific categories as subspecies, nor all the relevant literature since that information has been included by the author of the last published checklist (Mock 2001a). References are listed at the species where the first records for Slovakia were documented for the first time after the year 2000. In addition, habitat evaluation for each species is included, applied specifically to the area of Slovakia, following adapted categorisation proposed by Tuf and Tufová (2008) and marked by a letter in caps:

•
Relic species (R) -stenotopic species inhabiting exclusively undisturbed habitats with low impact of human activities, for example, the nature-closest forests, remnants of steppes, caves, stony debris, mountain habitats. • Adaptable species (A) -species inhabiting nature-close habitats (various types of forests or meadows), able to penetrate artificial and man-made habitats (parks, abandoned gardens, graveyards, greenhouses etc.). • Eurytopic species (E) -species with the widest ecological valence, frequently found in forested and non-forested biotopes and in man-made plots (fields, brownfields etc.). • Synanthropic species (S) -species inhabiting a wide spectrum of man-made habitats, missing in natural biotopes, species significantly synanthropic, although occasionally found in natural, mainly altered, sites. • Exotic species (X) -this category includes mostly tropical species, non-native or introduced species, found exclusively in hothouses.
Ecological classification of each species (Kime and Enghoff 2011, Kime and Enghoff 2017) is provided in Notes, marked by lowercase letters: We would like to note that we did not adopt this habitat evaluation scheme mechanically, but we evaluate each species, based on the knowledge about its ecology in Slovakia. Question mark (?) next to the classification refers to problematic data on the occurrence of the species.
In addition, a general geographical category that outlines the distribution of each species is included in the list (Kime and Enghoff 2011, Kime and Enghoff 2017).

Data resources
Records from Slovakia compiled from the published literature and additional collected material are summarised. The actually sampled material is in the collection at the workplace of the authors' team. Part of the data was obtained by preliminary revision of the collection by J. Gulička, including his unpublished compendia. A large portion of Gulička's complete written legacy is lost. However, his views on the taxonomy, biogeography and ecology of individual species can be found in Gulička's additionally handwritten notes in the monographs of other authors (e.g. Verhoeff 1928, Schubart 1934.

Updated list of the millipede fauna of Slovakia
Order Polyxenida

Distribution: West Palearctic and Nearctic
Notes: A, c, n

Order Glomerida
Notes: The order Glomerida, according to published data, is represented by three genera in Slovakia -Trachysphaera, Glomeris and Geoglomeris (Lang 1954, Kime and Enghoff 2011, Kime and Enghoff 2013, Kocourek et al. 2017). Genus Glomeris is rather problematic, as it represents a complex of species, characterised by inconsistency and unreliable determination information in the old literature. G. tetrasticha, G. hexasticha and G. pustulata represent well-confirmed species, occurring in the territory of Slovakia. Only one old record of G. klugii from Slovakia exists. In the area of Slovakia, some populations of the species of the genus Glomeris are characterised by a remarkable variety of colouration, which could indicate the ongoing speciation processes. The species (known under synonyms G. conspersa and G. undulata in older literature) is characterised by a south-western occurrence in Europe (Kime and Enghoff 2011). It has been confirmed in most of the neighbouring countries (Poland, Czech Republic, Austria and Hungary). For Slovakia, only one record of this species has been recently discovered, in the millipede collection of Czech arachnologist František Miller , housed in the National Museum, Prague (Dolejš and Kocourek 2020). One female specimen of G. klugii is included in the collection, labelled with April 1930, Turčianske Teplice District, Žilina Region. Based on this information, a series of sampling from this area has been conducted, but unsuccessfully. Therefore, a mistake in localisation made by collector is highly possible.

Notes: R, e
Glomeris mnischechi is considered the only endemic species of the order Glomerida north of the Alps. According to Kime and Enghoff (2011), the species inhabits mountainous biotopes of Slovakia (Belianske Tatras Mts., Pieniny Mts.) and Poland. However, literature contains many controversial data about diagnostic characteristics, as well as ecological demands (Mock 2001a, Kravcová and. Nowicki originally offered two descriptions of G. mnischechi ( Nowicki 1870, Nowicki 1871, without any illustration. In addition, the author used different transcription for the species names in both cases, Glomeris mnischechi ( Nowicki 1870) and Glomeris mniszechii ( Nowicki 1871). After this confusion, the species was described several times in the old literature, under various synonyms (Latzel 1884, Gulička 1951, Gulička 1960a, Dziadosz 1966. Other authors considered the species to be subspecies of G. hexasticha, due to the striking similarity of both species (e.g. Jawlowski 1938).
Although the taxonomic status of the species remains unresolved, recent molecular analyses of several representatives of G. hexasticha from the type locality of G. mnischechi suggest the presence of several separate species; therefore, the existence of G. mnischechi and its occurrence in Slovakia cannot be ruled out.  Verhoeff (1908) from the neighbourhood of Dresden, Germany, where two females were found on limestone near a brook. In his monograph on the millipede fauna of Czechoslovakia, Lang (1954) presented the finding of G. subterranea in the only Slovak locality from the vicinity of the Bratislava City (Malé Karpaty Mts.). However, he did not comment on the finding and attached only a picture taken from other literature (Schubart 1934). Since the cited monograph contains many ambiguities and unreliable data, this information is considered doubtful (Gulička 1986, Mock 2001a). In the area of Slovakia, it was found only recently (Haľková et al., unpublished), repeatedly, in karst springs and wetlands on karst bedrock. Detailed morphological study (including SEM), supported by molecular analysis, confirmed the identity of G. subterranea, without any apparent morphological adaptations to aquatic and semi-aquatic habitat. The possibility that this species is not strictly limited to the terrestrial environment has already been suggested by Noll (1939), although his findings were completely forgotten in recent literature. Noll mentioned the presence of Geoglomeris jurassica (a younger synonym of G. subterranea) in the water of three wells in Northern Bavaria, Germany. The author explained its occurrence as random, presuming the animals entered the well through crevices in the wall. Species with European distribution, in Britain and Ireland found beneath the bark of dead deciduous tree trunks and stumps (Blower 1985). It appears to be predominantly or entirely synanthropic in most other countries, occurring primarily in cities and cultivated areas (Kime and Enghoff 2017). The same applies to the first findings of the species in Slovakia, where it was found in city parks. Most of the unclear and questionable data that were preliminarily excluded from the list are from the older literature. One of the most recent studies, creating confusion due to imprecision in accurate and reliable determination, was published by Topp et al. (2006). The authors investigated the biodiversity of woodlice and millipede faunas of the primeval forest of Central Slovakia. The authors' team, however, lacked a taxonomist and, as a result, species not occurring in our country or species with strictly synanthropic occurrence were listed, such as such as  Holdhaus 1954). The presence of a significant proportion of endemic fauna characterises the millipede fauna of Slovakia as exceptional in Central Europe. Gulička and Košel (2016) have mentioned the presence of 28 Carpathian endemic species of millipedes in Slovakia. A large part of these species is defined as Western-Carpathian. However, the border between the Eastern and Western Carpathians crosses the eastern part of the country, resulting in the representation of the eastern Carpathian fauna. Nevertheless, it should be noted that this border is not strict and is not consistent for all the species. For some species, the term Northern-Carpathian endemic is more appropriate. Some species even can be characterised by microendemism (e.g. Leptoiulus tatricus, Mecogonopodium carpathicum and Hylebainosoma gulickai). The presence of the Western Carpathians has an undeniable influence on the composition of Slovak millipedes. Almost 20% of the species are represented by rare mountainous fauna and more than 10% are characteristic for their preference of cave habitat.

Cylindroiulus burzenlandicus
According to ecological classification, 50% of Slovak millipede fauna are represented by stenotopic species inhabiting exclusively undisturbed habitats with a low impact of human activities. A total of 20% can be classified as adaptable and only 7% can be classified as eurytopic. While the original classification, proposed by Tuf and Tufová (2008), is applicable to most of the species, the categorisation does not sufficiently segregate nonnative, introduced species occurring exclusively in a specific environment (e.g. tropical species in greenhouses). Therefore, we added and used two categories to this classification, in order to distinguish synanthropic and exotic species. These categories include the remaining 13% of millipede species of Slovakia.
Despite the increased interest in faunistic research, the millipede fauna of Slovakia has not yet been completely investigated. Several findings are still to be determined at the species level. Such findings include subadult and female individuals of Typhloiulus sp. from the Domica Cave (Papáč et al. 2014) and a representative of the family Trichopolydesmidae (Akkari and Enghoff 2011). Both taxa are connected to the cave environment.