ИСТИНА

A presumably new species of Styraconyx (Arthrotardigrada, Halechiniscidae) was discovered in a marine aquarium settled in Pacific Geographical Institute, Petropavlovsk-Kamchatsky, Russia. Abundant tardigrade specimens were found within a sparse of silty sediment in an aquarium containing nothing but tufts of Chaetomorpha alga. The genus Styraconyx contains 13 species recorded worldwide incl. Arctic, temperate and tropical zones; however, individual species are selective in choice of substrate. The newly found species distinctly differs from other known species in sculpture of dorsal surface (transversal ridges) as well as in details of toes and claws, and shape of primary clava. The native area and habitat of the species is not known. The aquarium was initially filled with «living stones» imported from Indonesia – hence it is possible to suppose this tardigrade is epiphytic tropical Indo-West-Pacific species. The phylogenetic analysis based on 28S rRNA gene sequences nests the investigated species within the genus Styraconyx. The study is supported by RFBR grant 15-04-02597. 1Department of Invertebrate Zoology, Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia; Kamchatka Branch of Pacific Geographical Institute, Far-Eastern Branch of the Russian Academy of Sciences, Partizanskaya 6, Petropavlovsk-Kamchatsky, 683000, Russia; 3Pertsov White Sea Biological Station, M.V. Lomonosov Moscow State University, Moscow, Russia.