About Georgian Cave Fauna

The cave fauna of Georgia, Caucasus has been recognized as unique on a global scale, but has yet to be studied comprehensively. Altogether, 453 invertebrate species belonging to 45 orders from 18 classes and 7 phyla are recorded from 134 caves in Georgia (Barjadze et al., 2015; Antić & Makarov, 2016; Sidorov, 2016; Sidorov, & Samokhin, 2016; Turbanov, Palatov, & Golovatch, 2016; Marin, 2017; Vargovitsh, 2017; Golovatch & Turbanov, 2017, 2018; Antić, Turbanov, & Reboleira, 2018; Sidorov, Taylor, Sharina, & Gontchariv, 2018; Vinarski & Palatov, 2018). Investigations of Georgian cave invertebrates began in the 19th century (Boettger, 1879) and have dealt primarily with taxonomic, faunistic and zoogeographic topics (Barjadze et al., 2015; Turbanov et al., 2016), with information on ecology rarely receiving attention in this literature. A notable exception is an ecological contribution on the distribution and comparative analysis of the aquatic cave fauna of Apkhazeti (= Abkhazia) (Chertoprud et al., 2016). Ecological investigations of the cave fauna are hindered by the inaccessibility or at least difficult accessibility of many caves. Consequently, the existing data on the cave-dwelling invertebrates do not show a complete picture of the biodiversity of Georgian caves.

Of the 453 invertebrate species recorded in the Georgian caves, 86 species are obligate cave dwellers (18.9% of all species): 43 of these are terrestrial (troglobionts s.str.) and 43 are aquatic (stygobionts). The troglobionts include 38 arthropod and 5 mollusk species, while stygobionts include 31 arthropods, 10 mollusks, one annelid and one ciliophora species. Of the 86 hypogean species recorded from 61 caves in Georgia, Caucasus, 58 were present in caves in Apkhazeti and 31 in caves of the central part of Western Georgia: Samegrelo, Racha-Lechkhumi and Imereti.

Locally endemic species known from only a single cave include 32 troglobites and 21 stygobites. The family Zenkevitchiidae Sidorov, 2018 is endemic of Georgia, and the following 13 troglobitic and stygobitic genera are also endemic to Georgia: Adaugammarus Sidorov, Gontcharov & Sharina, 2015; Kruberia Sidorov & Samokhin, 2016; Zenkevitchia Birstein, 1940 (Amphipoda); Lesticulus Schileyko, 1988; Motsametia Vinarski, Palatov & Glöer, 2014 and Pontohoratia Vinarski, Palatov & Glöer, 2014 (Gastropoda); Borutzkyella Tabacaru, 1993, Colchidoniscus Borutzky, 1974 and Mingrelloniscus Borutzky, 1974 (Isopoda); TroglopalitesVargovitsh, 2012 (Collembola); Leucogeorgia Verhoeff, 1930 (Diplopoda); Inotrechus Dolzhansky & Ljovuschkin, 1989 and Taniatrechus Belousov & Dolzhanskij, 1994 (Coleoptera). Four troglobitic genera are endemic to the Caucasus: Conulopolita Boettger, 1879 (Gastropoda); Jeannelius Kurnakov, 1959, Meganophthalmus Kurnakov, 1959 and Troglocimmerites Ljovuschkin, 1970 (Coleoptera).

The Georgian cave fauna is still insufficiently known, with only about 10% of karst and conglomerate caves having been investigated biospeleologically. Based on our current knowledge, the most widespread obligate cave invertebrates of Georgia include Trichoniscus aphonicus Borutzky, 1977 (14 caves), Zenkevitchia admirabilis Birstein, 1940 (8 caves), Niphargus inermis Birstein, 1940 (8 caves), Zenkevitchia yakovi Sidorov, 2015 (6 caves), and Conulopolita raddei (Boettger, 1879) (5 caves). The remaining species have narrower distributions and are known from 1–4 caves. Species richness is highest in Kveda Shakurani Cave (18 species), and other important caves for obligate subterranean species include Tsebelda (14 species), Akhali Atoni (8 species), Otapistavi (8 species), Sapichkhia (8 species), Shroma (7 species), Abrskili (6 species), and Shua Shakurani (6 species). The remaining caves are known to contain 5 or less obligate subterranean species.