COXI based phylogenetic analysis of Caucasian clade of European Troglocaris (Crustacea: Decapoda: Atyidae) with the suggestion of a new taxonomic group structure

Abstract

New genetic data on Caucasian troglobiotic shrimps collected from the territory of Russia, Abkhazia and Western Georgia are presented. Based on new genetic data on the marker region of subunit I of cytochrome oxidase of mitochondrial DNA (COXI mtDNA) of Caucasian species and other taxa of European cave shrimps (Troglocaris s.l.) from GenBank (NCBI) database, a new generic structure is presented. Based on a significant genetic divergence of COXI mtDNA subgenera of Troglocaris s.l., namely Troglocaris s.s., Xiphocaridinella and Spelaeocaris, should be considered as separate genera while Troglocaris (Troglocaridella) hercegovinensis (Babić, 1922) is suggested to be transferred within Dinaric genus Spelaeocaris as Spealeocaris hercegovinensis (Babić, 1922) comb. nov. Besides, Troglocaris bosnica shows a significant a genetic difference (at the level of the separate genus) from the remaining representatives of the genus Troglocaris s.s. Moreover, p-distances (COXI) of about 17% are supposed for generic separation within European Troglocaris-related atyid shrimps and 5% for separation of cryptic species within Caucasian Xiphocaridinella. A list of all known taxa of Troglocaris-related atyid shrimps of the European part and a discussion of the general distribution of troglocaridid atyid shrimps in the Balkans and the Caucasus are presented. A new version of divergence events between Dinaric–Caucasian Troglocaris lineages (genera) based on new genetic data is suggested.

Thoridae (Crustacea: Decapoda) can penetrate the Abyss: a new species of Lebbeus from the Sea of Okhotsk, representing the deepest record of the family

“…7). The genetic p-distances (Table 2) between these species are lower than previously documented for caridean shrimps (Knowlton et al 1993;Knowlton & Weigt 1998;Hebert et al 2003;Sites & Marshall 2004;Zakšek et al 2007;Lefébure et al 2006aLefébure et al , 2006bMarin 2017).…”

Crustacean “cave fishes” from the Arabika karst massif (Abkhazia, Western Caucasus): new species of stygobiotic crustacean genera Xiphocaridinella and Niphargus from the Gegskaya Cave and adjacent area

“…The genetic divergence (p-distances) of COI mtDNA gene marker between Xiphocaridinella dbari and other Caucasian Xiphocaridinella species correspond to characteristic interspecific values calculated for Decapoda and cave shrimps ( Fig. 10; Table 1) (after Knowlton et al, 1993;Knowlton, Weigt, 1998;Hebert et al, 2003;Sites, Marshall, 2004;Zakšek et al, 2007Zakšek et al, , 2009Lefébure et al, 2006a, b;Marin, 2017bMarin, , 2018a DESCRIPTION. Body moderately slender.…”

“…Data on "molecular clocks" used in Troglocarislike cave shrimps, including Caucasian Xiphocaridinella, as a sequence (COI mtDNA) divergence rate about 1.4-2.4% of substitutions per site on 1MYA [Knowlton et al, 1993;Knowlton, Weigt, 1998;Zakšek et al, 2007;Jugovic et al, 2012] calculating the splitting time within the Caucasian lineages/species from ~2.0 to ~10.0MYA) (see Marin, 2017b; Table 1). Using known data, it is possible to assume two separate divergence events within Dinaric-Caucasian Xiphocaridinella lineages (genera) occurred about 9-15MYA (ancestor of Troglocaris separated from Spelaeocaris-Xiphocaridinella) and about 8-13MYA (ancestor taxon diverged for Dinaric Spelaeocaris and Caucasian Xiphocaridinella [Marin, 2017b]). It is difficult to compare this time with any geological events, and the divergence rates should be revised upwards in the percentage of substitutions by 1MYA [Marin, in prep.…”

“…Values of confidence >50% are presented for ML, NJ and BA analyses (bootstraps); the divergence of pairwise genetic distances (p-distances) was calculated using the Kimura-2-parameter (K2P) model in MEGA 7.0. The species delimitation is carried out according to the latest understanding of the interspecific distances at cave crustaceans [Zakšek et al, 2009[Zakšek et al, , 2019Copilas-Ciocianu et al, 2017;Deliae et al, 2017;Marin, 2017bMarin, , 2018a. DESCRIPTION.…”

Euxinian relict amphipods of the Eastern Paratethys in the subterranean fauna of coastal habitats of the Northern Black Sea region

“…At the same time, the Caucasus is the second region of the Western Palearctic (after the Balkan Peninsula) in term of karst area size, variety of landscapes and climatic conditions (e.g., Myers et al, 2000;Krever et al, 2001). Since 2010, recent biospeleological studies in the Crimean Peninsula, the Russian Caucasus and the adjacent regions of Abkhazia have focused mainly on the diversity and ecology of the diplopods (Golovatch, 2011;Golovatch, Chumachenko, 2013;Golovatch et al, 2016;Antić, Makarov, 2016;Antić et al, 2018;Antić, Reip, 2020), cave carabid beetles (Belousov, Koval, 2009Giachino, 2011;Reboleira, Ortuno, 2014) and arachnids (Tchemeris, 2013), cave shrimps (Marin, Sokolova, 2014;Marin, 2017Marin, , 2018Marin, , 2019Marin, , 2020Marin, Turbanov, 2021), crangonyctid (Sidorov, 2015) and gammarid amphipods (Sidorov et al, 2015a(Sidorov et al, , b, 2018Sidorov, 2016;Sidorov, Samokhin, 2016), woodlice (Gongalsky, Taiti, 2014;Turbanov, Gongalsky, 2016), springtails (Collembola) (Jordana et al, 2012;Vargovitsh, 2012Vargovitsh, , 2013, false scorpions (Kolesnikov, Turbanov, 2020), stygobiotic gastropods (Vinarski et al, 2014;Grego et al, 2017Grego et al, , 2020Vinarski, Palatov, 2019;Chertoprud et al, 2020Chertoprud et al, , 2021 and some other subterranean animals (e.g.,…”