Fauna of Coregonus sardinella Parasites of the Indigirka River

The purpose of the research is studying fauna of Coregonus sardinella parasites of the Indigirka River. Materials and methods. The studies were carried out in August–September 2015–2017 in the lower reaches of the Indigirka River. A total of 421 specimens of C. sardinella were studied using partial parasitological autopsy method, of which: 227 specimens aged from 2+ to 12+ in 2015, 31 specimens aged from 4+ to 8+ in 2016, 163 specimens aged 2+ to 12+ in 2017. We used the determinant of parasites of fresh-water fish of the USSR fauna to determine the species affiliation of the revealed parasites. The infection intensity, and abundance index were assessed. Results and discussion. 12 species of parasites were found in C. sardinella of the Indigirka River, namely, 1 species of protozoa, 4 species of cestodes, 3 – nematodes, 1 species of scrubs, 1 species of leeches, 2 species of parasitic crustaceans. Among the parasitic diseases of C. sardinella that are dangerous to human health, diphyllobothriosis is registered, and trienophorosis is among those that affects the marketable appearance of fish. High infection of C. sardinella with Diphyllobotrium sp. in the water area of the Indigirka River has been observed for several decades, which suggests its leading role in the circulation of this helminth in the studied reservoir. The study of the fauna of C. sardinella parasites show the need for continuous monitoring of fish infection rates to prevent possible epizootics and even death of juvenile fish.

A restudy of the generic composition of the linyphiid spider fauna of the Far East (Araneida: Linyphiidae)

The generic composition of the Far Eastern linyphiids has been restudied. The following 9 new genera are established: Nippononeta gen.n. (9 species, including N. kurilensis sp.n.). Neserigone gen.n. (3, including N. basarukini sp.n.). Saitonia gen.n. (4). Paikiniana gen.n. (3), as well as Bathylinyphia gen.n., Orientopus gen.n., Parhypomma gen.n., and Baryphymula gen.n., all monobasic. The genera new for the Far East are Trichoncus (T. orientalis sp.n. and T. hyperboreus sp.n.) and Ceratinops (C. amurensis sp.n. and C. kolymensis sp.n., forming a separate subgenus Asiceratinops subgen.n.); Gongylidioides (C. ussuricus sp.n.) is a genus new for the USSR fauna. New combinations are proposed for 10 species (2 transferred to the genera Eperigone and Turinyphia, both new for Far East); further 4 species are excluded from the family Linyphiidae.

The Occurrence of Polymely and Polydactyly in Natural Populations of Anurans of the USSR

Various cases of isolated and mass polymely and polydactyly in anurans of the USSR fauna are summarized. Mass polydactylies in frogs Rana arvalis arvalis and Rana lessonae-Rana esculenta as well as in toad Bufo bufo bufo are reported. Classiication of polydactyly types based on X-ray analysis is proposed. Species-specificity and lozalized appearance of mass polydactyly factor(s) are discussed.