Contribution to the knowledge on the distribution of Recent free-living freshwater ostracods (Podocopida, Ostracoda, Crustacea) in Slovenia

. An updated checklist of Recent free-living freshwater ostracods (Podocopida, Ostracoda, Crustacea) from Slovenia together with new records is presented. The new checklist is based on both the records extracted from the literature and the sampling in the field carried out during the last decade. The present checklist comprises 61 species. However, the eastern part of Slovenia and the surface waters are underrepresented. It is expected that the number of species will increase in the future.


Introduction
Despite the fact that Slovenia is being recognized as a biodiversity hotspot, a preliminary list of Recent free-living freshwater ostracods (Podocopida, Ostracoda, Crustacea) from Slovenia reports only 47 species (Griffiths & Brancelj 1996a).For comparison, in Western Europe, without the Mediterranean and Dinaric regions, 158 species (Meisch 2000) and, at the global scale, 2090 species belonging to about 209 genera are known at present (Martens & Savatenalinton 2011).
Petkovski & C. Meisch in 1994 (Cypria bicolor Petkovski & Meisch, 1994).The first species was collected from the spring Rak near Cerknica (Danielopol 1982) and the second one from the spring Ižica near Ljubljana (Petkovski & Meisch 1994).At the end of the last century, H. Griffiths carried out a sampling campaign of mostly Alpine lakes and co-authored the preliminary checklist for Slovenia (Griffiths & Brancelj 1996a) as well as a paper about the palaeo-biogeography of Candona bimucronata in the Balkans, including Slovenia (Griffiths & Brancelj 1996b).
In 2002, an extensive field sampling was carried out in the karst and alluvial aquifers south of Ljubljana with the aim to assess the groundwater biodiversity of the area and compare it to other European regions (EU PASCALIS project, Dole-Olivier et al. 2009, Mori et al. 2011a).On that occasion, the present authors started to collaborate on the taxonomy and distribution of the freshwater ostracods in Slovenia.After that, ostracods were continuously collected and identified during several field samplings carried out by the National Institute of Biology (Mori & Brancelj 2011, Mori et al. 2011b, 2012).
The present paper summarizes the history of ostracod research in Slovenia and presents an overview of all the species recorded in this country until the present.Additionally, it provides a list of unpublished new records for Slovenia, with information on their geographical location and habitat type.The species list includes the species that were previously reported in the literature and records that were obtained through field sampling by the first author during the last 10 years.It provides general information on geographical distribution, the habitats where species were collected and lists all the publications in which the species were reported.This work provides an updated information on the occurrence of this neglected crustacean group in Slovenia and demonstrates, as it was shown by many other specialists, that Slovenia is a biodiversity hotspot (Sket 1999) also as far as ostracods are concerned.

Material in methods
Only Recent free-living freshwater ostracods were considered in this work.First, a careful examination of the existing original literature reporting on the occurrence of ostracods in Slovenia during the last two centuries was carried out.Based on this literature, a new species list was composed in order to update the nomenclature and to avoid possible errors from the preliminary check list published by Griffiths & Brancelj (1996a).Next, the data obtained from the first author's field samplings, starting in 2002, are included.Hence, the present species list contains all the species reported in the literature published since 1920 (Brancelj et al.The list of locations for the species collected by the first author from 2002 onwards is provided.That list contains the geographical name of the corresponding location, the habitat type, Gauss-Krüger coordinates, altitude, date of collecting and the name of the persons who collected the sample and identified the species.The localities selected during the EU PASCALIS project were sampled by several different field workers from NIB and Biotechnical Faculty in Ljubljana and their names are not specified. In the species list, a valid species name, the general information on geographical distribution based on the phytogeographic division of Slovenia (AL -Alpine, SA -Subalpine, SM -Submediterranean, DN -Dinaric, SD -Subdinaric, SP -Subpannonian) (Wraber 1969) and habitats types where the species was collected are provided.Additionally, for each species, the publications where the species was reported until present are cited.For each genus, the type species is marked by asterisk (*).

Discussion
The intensive field sampling and taxonomical work carried out during the last ten years resulted in several new Ostracoda records for Slovenia.At present, 61 species belonging to 25 genera and 6 families are listed for Slovenia.Moreover, several new species to science need to be described.Altogether, only 23 papers have been published from 1882 until present that report on original findings of Ostracoda in Slovenian freshwaters.Since the focus of the first author's research work are groundwaters in the southern (Dinaric region) and northwestern Slovenia (Alpine region), the surface species and species that are distributed in the eastern Slovenia (Subpannonian region) are still underrepresented.
The present checklist comprises species with a wide distribution across the whole of Europe as well as a number of groundwater species which are most probably endemic in Slovenia and/or the Dinaric region.In the Slovenian Red list of endangered crustaceans, five ostracod species were reported as single site endemics (C.reptans, F. aemonae, T. cavicola, T. trigonella and T. pretneri) (Sket & Brancelj 1992).After the intensive sampling of groundwater habitats (karst and alluvial aquifers) of Slovenia, it is clear that the first three species are widespread across southern and western Slovenia.The taxonomical position of the last two species is currently under revision, from which it appears that at least T. pretneri is a synonym with T. cavicola (Meisch & Mori, in preparation).Further, as proposed by Griffiths & Brancelj (1996a), the intensification of field sampling resulted in records of several species from the genera Fabaeformiscandona and Mixtacandona that had earlier not been included in a preliminary list even with a single species.It is expected that future data collection from the surface waters and from the eastern part of the country will further increase the number of recorded species and that a number of species currently considered as »single site« species will be more widespread.