Marin I.N.1, Krylenko S.V.2, Palatov D.M.1 2021. Euxinian relict amphipods of the Eastern Paratethys in the subterranean fauna of coastal habitats of the Northern Black Sea region // Invertebrate Zoology. Vol.18. No.3: 247–320 [in English].
2 Biological Faculty, M.V. Lomonosov Moscow State University, Moscow, 119992 Russia. E-mail: firstname.lastname@example.org
ABSTRACT: The article presents the first insight into the diversity and distribution of the relatively small Niphargus “tauricus” ingroup of the “stygius” species group (Crustacea: Amphipoda: Niphargidae) living in the coastal caves/springs of Dobrogea in Romania, the Crimean Peninsula and the south-western foothills of the Caucasus Mountains. Six species, namely Niphargus utrishensis Marin et Palatov sp.n., N. novorossicus Marin et Palatov sp.n., N. alisae Marin, Krylenko et Palatov sp.n., N. ashamba Marin, Krylenko et Palatov sp.n., N. malakhovi Marin et Palatov sp.n. and N. dederkoyi Marin et Palatov sp.n. are described from the Black Sea coastal foothills of the south-western part of the Caucasus Mountains. Crimean N. tauricus Birљtein, 1964 is re-described based on topotypic material. Morphological diagnoses and descriptions for all species of the “tauricus” ingroup as well as the key for their identification are presented. Aside from the morphological comparisons, DNA barcode (COI mtDNA gene marker) is employed for their identification. It is assumed that these species are Euxinian relicts of the Eastern Paratethys and were settled in their current habitats at the end of the Miocene at least 5 Mya. According to the data obtained, the related species of the ingroup are confined to the same mountain ridge, which suggests that the settlement occurred by several “waves”. At the same time, we suppose that the modern species distribution is shaped rather by the uplift of Caucasian coastal mountain ridges and karst fragmentation occurred during the the last 2–3 Mya (since Late Pliocene – Early Pleistocene) than the fluctuation of the sea level. Because these animals are not able to disperse actively, we believe that these unique ancient genetic lineages (species) and their biotopes (underground water habitats) are in need of especial protection.
KEY WORDS: diversity, Niphargus, phylogeny, phylogeography, taxonomy, barcoding, subterranean, relicts, foothills, Caucasus, Crimean Peninsula.