D. M. Palatov’s research while affiliated with Severtsov Institute of Ecology and Evolution and other places

Illustrated description of adult male, as well as DNA barcoding, of Thalassomya paraskevae sp. nov. in comparison with close related species T. frauenfeldi Schiner from coast of the Black Sea are provided. Interspecific p-distances using gene COI 5P between T. paraskevae sp. nov. and T. frauenfeldi from Madeira (Portugal) were 8.94%. Divergence between described species and T. frauenfeldi collected near the type locality (Friuli Venezia-Giulia, Italy) using COI 3P were 7.72%. Obtained values corresponds to species level.

Two new Caucasian species of the genus Niphargus Schiödte, 1849 (Crustacea: Amphipoda: Niphargidae), N. rachalechkhumensis sp. nov. and N. tvishiensis sp. nov., are described from the stygobiotic habitats of the Racha-Lechkhumi and Kvemo Svaneti karst systems in Western Georgia. Both newly described species belong to the southwestern Caucasian “Niphargus borutzkyi” ingroup related to the European “carphaticus” species complex and can be clearly separated from the congeners by morphological features, mostly in uropod III and epimeral plates, and genetically. Identification key for all known species to the “Niphargus borutzkyi” ingroup is provided, as well as their phylogenetic relationships, the estimated time of the origin and the current distribution of the ingroup in the Colchis lowland of the southwestern Caucasus are also discussed.

Five Filchneria Klapálek, 1908 (Plecoptera, Perlodidae) species known since the last century (F. balcarica Balinsky, F. mesasiatica Zhiltzova, F. irani (Aubert), F. kuenluensis (Šámal), and F. olgae (McLachlan)) were redescribed on types stored in museums in the Netherlands, Switzerland, Russia and newly acquired material. The redescription were in accordance with the requirements of modern taxonomy, illustrated with color photographs of the habitus, head, pronotal patterns, eversible male paraproct lobes, male paraproctal sclerite, aedeagus (as possible), details of chaetotaxy, female subgenital plate, and egg using digital cameras and SEM. The diagnostic features of each species are revealed. The main differences were established in the male paraproctal sclerite shape, in the posterior margin of tergum 10, the female subgenital plate, and the egg structures. After reexamining the syntype series of Filchneria olgae, a lectotype is designated for this species. Filchneria kuenluensis is proposed to transfer to Perlodinella Klapálek, 1912 with the valid name Perlodinella kuenluensis (Šámal, 1935) comb. nov. Filchneria shobhaae is considered as a junior synonym of Zhiltzovaia amabilis (Jewett, 1958) syn. nov.

The results of a revision of the Diamesa steinboecki group, namely soubgroups steinboecki and longipes (Diptera, Chironomidae, Diamesinae) are presented. Illustrated descriptions of the adult male of D. dragani sp. nov. from Sayan Mountains, D. kownackii sp. nov. from Wrangel Island, D. maisaraensis sp. nov. from Pamir, D. marinskiyi sp. nov. from Tian-Shan, D. zagrosica sp. nov. from Iran, D. moubayedi sp. nov. from Lebanon are provided with redescriptions of D. steinboecki Goetghebuer from Pamir, French and Swiss Alps, D. sakartvella Kownacki et Kownacka from Caucasus and D. praecipua Saether et Willassen from Himalayas. Taxonomic remarks with data on the ecology and biogeography of the investigated species are given. In addition to taxonomic information, 658-bp fragments of the mitochondrial cytochrome oxidase subunit I gene from the eight species are presented and the results of DNA barcoding are discussed. Previous investigations focused to integrative taxonomy and molecular analysis of the Diamesa species collected in various mountain regions such as Alps, Tien Shan and Pamir. In the present work, we focused on the principle of considering morphological groups, giving more emphasis respect to the division in geographical areas.

The article presents a morphogenetic revision of the relatively small Niphargus “tauricus” ingroup of the “stygius” species group (Crustacea: Amphipoda: Niphargidae), that lives 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., Niphargus novorossicus Marin et Palatov sp.n., Niphargus alisae Marin, Krylenko et Palatov sp.n., Niphargus ashamba Marin, Krylenko et Palatov sp.n., Niphargus malakhovi Marin et Palatov sp.n. and Niphargus dederkoyi Marin et Palatov sp.n. are described from the Black Sea coastal foothills of the south-western part of the Caucasus Mountains. Crimean Niphargus tauricus Birštein 1964 is re-described based on topotypic material. Morphological diagnoses, key for species identification, as well as molecular sequence data (COI mtDNA gene marker) are represented for all species of the “tauricus” ingroup. 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.

Four epigean species of the genus Niphargus Schiödte, 1849 (Crustacea: Amphipoda: Niphargidae), namely N. hrabei S. Karaman, 1932, N. valachicus Dobreanu et Manolache, 1933, N. magnus Birštein, 1940, N. potamophilus Birštein, 1954, were recorded as pond dwellers on the coastal plains of the Black and Azov seas of the north- and south-western Caucasus. Niphargus potamophilus and N. magnus were re-described based on topotypic material; the first species is distributed in the lower part of the coastal plain of the Sea of Azov between the deltas of the Kuban and Don rivers, while the latter taxon is a complex of several cryptic species that are widely distributed in the Kolkhida coastal lowland plain of the eastern Black Sea (Colchis) from Russia to the north-eastern Turkey. Niphargus cubanicus Birštein, 1954 was found to be a junior synonym of N. hrabei, which was firstly reported from the Russian Caucasus, in the upper part of the coastal plain of the Sea of Azov from the Kuban River delta. N. valachicus was firstly reported from the Colchis near Poti, Georgia. Neotypes based on topotypic material were selected for N. potamophilus and N. magnus, since the original type material was lost. Molecular genetic data for these Caucasian species are presented for the first time.

Nemoura lepnevae Zhiltzova, 1971, Amphinemura mirabilis turkestanica Zhiltzova, 1978, Capnia s.l. longicauda Zhiltzova, 1969 and Mesoperlina pecirkai Klapálek, 1921 are reported for the stonefly fauna of China for the first time. The species were collected in the Bogdo-Ula and Karlyktag Ranges of the Eastern Tian Shan Mountains, the Xinjiang Uygur Autonomous Region. In addition, a detailed redescription of Filchneria wusuensis Chen, 2019 including new illustrations is provided.