Vol 7, No 3 (2016)

A new species of polychaete of the Sabellidae family, Pseudopotamilla reniformis (Bruguière, 1789), was found for the Black Sea near the coast of eastern Crimea. It was registered on rocks at the depth of 2–3 m in the area of Sevastopol (Kazach’ya Bay) in 2003 and at Cape Tarkhankut in 2011.

The Ponto-Caspian cladoceran Evadne anonyx (G.O. Sars, 1897) was recorded in the summer zooplankton of the Southeastern Baltic (SEB) in 2010–2011. The quantitative parameters of the species were low. The share of the introduced species in the total abundance and biomass of zooplankton was not significant. The population of E. anonyx was represented predominantly by parthenogenetic females with 1–22 eggs. Among individuals, males were found and that allowed the suggestion of the presence of sexual reproduction and formation of gamogenetic eggs in the populations of E. anonyx in the SEB. Morphometric parameters of populations of E. anonyx and fertility of parthenogenetic females in the SEB were comparable with those of Caspian forms. It is possible that, with the emergence of the new species E. anonyx, structural and functional changes may take place in zooplankton community of half-closed Curonian and Vistula lagoons of the Baltic Sea.

In November 2013 in Vostok Bay (Peter the Great Bay, Sea of Japan), in the fouling of the experimental installation of the Mytilus trossulus mussel culture, mass settlements of colonial ascidian not previously observed in Peter the Great Bay were registered. The taxonomic identification of colonial ascidians is rather complicated, and frequently the morphological and genetic methods of the species determination do not give a clear result. The usage of molecular-phylogenetic methods allowed us to indicate the sequences of nucleotides obtained from three colonies of ascidians from Vostok Bay as inherent to the invasive species Didemnum vexillum Kott, 2002. This species is known as an invasive in aquaculture settlements of mussels and oysters in various regions of the World Ocean in different years.

The role of invasions in formation of the phylogeographic structure of a synanthropic species of house mouse (Mus musculus) is investigated. The probable ways of its expansion in some areas of Russia and the near abroad are analyzed. The genetic variability of subspecies and populations of M. musculus is evaluated by the data on polymorphism of the mitochondrial DNA control region (D loop). The data show that there are three phylogenetic varieties of house mice living in Russia and the near abroad: (i) house mice from the hybrid zone in Transcaucasia and М. m. musculus from Moscow; (ii) house mice of southern European Russia and southern Western Siberia; (iii) populations of M. m. musculus from Eastern Europe. The invasions caused nonuniformity of the phylogeographic structure of M. musculus. None of the studied subspecies (M. m. musculus, M. m. wagneri, and M. m. gansuensis) formed a uniform phylogroup. This is probably related to hybridization of different parapatric taxa of house mice at the species and intraspecies levels.

The article provides data on allelic and genotypic diversity of Ukrainian and Armenian populations of a parthenogenetic lizard of Darevskia armeniaca. The individual genotypes of studied specimens were established due to combination of alleles of three microsatellite loci. It is supposed that in the introduced Ukrainian population after the invasion two new genotypes appeared. Molecular mechanisms of the emergence of these new genotypes are suggested. Values of observed heterozygosity and genetic Fst-distances for the introduced Ukrainian population, native Armenian population and group of other Armenian populations are provided.

The article presents new data on the northward expansion of the nesting range of great egret Casmerodius albus. Nests of great egret with adults and nestlings were found within a grey heron Ardea cinerea colony situated on Radovskii Island on the Rybinsk Reservoir in Yaroslavl oblast of Russia in late July 2015. This finding suggests that the nesting range of great egret is expanding toward the north of the European part of Russia.

A population of the Caspian bighead goby, an invader species expanding its range, has been found in the Moscow River within Moscow for the first time. It is the first known river population of bighead gobies in the Volga River basin. Results of the study of distribution, feeding, and growth of gobies are presented. Bighead gobies occupy in the river a peculiar artificial biotope—a breakwater made of big stones dumped into the water and adjacent sites of the bottom. The food base of bighead gobies in the Moscow River is composed of fish whitebait and to a lesser extent large invertebrates. A similar pattern of feeding of bighead gobies is observed in the Caspian Sea, but not in reservoirs of the Volga River. The growth rate of bighead gobies in the Moscow River is relatively high and only concedes to the growth rate of gobies from the Caspian Sea. Several assumptions on the invasive potential of the species are presented.