Аннотация:Although Russia is traditionally among best studied countries in the field of freshwater Cladocera (Crustacea: Branchiopoda), still there are many territories mysterious for the hydrobiologists. Eastern Siberia is a huge area (larger than whole European Subcontinent) with a minimal human population and plenty of hardly assessable water bodies. This region was studied sporadically in the past, but now all previous determinations of the Cladocera need to be re-checked after a recent strong progress in the taxonomy of this group.
Our aim was to study in detail the Cladocera of Central Yakutia, a lowland territory in the heart of Eastern Siberia. During 2010-2012, we collected and studied about 300 samples in pelagic and littoral zone of 152 water bodies of different types located in the Lena River basin (61-64°N; 127-134°E). Totally, 89 taxa of the Cladocera were found, with a great prevalence of littoral forms.
Specially interesting are finding of “American” taxa (or their closest relatives): Chydorus biovatus Frey, 1985, Daphnia dentifera Forbes, 1893, Disparalona acutirostris (Birge, 1879), Disparalona leei Chien, 1970, Megafenestra nasuta (Birge 1879). Some species definitively penetrated to Central Yakutia from South, like Bosmina tanakai Kotov, Ishida et Taylor, 2009, Diaphanosoma amurensis Korovchinsky et Sheveleva, 2009, Diaphanosoma pseudodubium Korovchinsky, 2000. Few species are endemics of northern portion of East Asia, such as Ophryoxus kolymensis Smirnov, 1992. At the same time, some common “European” taxa are definitively absent in Central Yakutia, like Chydorus sphaericus (O.F. Mueller, 1776). Several taxa are definitively new for science, like Limnosida sp. nov., Chydorus sp.nov., Ceriodaphnia sp.nov., they will be formally described later. Therefore we found the cladoceran fauna of Central Yakutia to be significantly different from those of other regions with adequately studied cladocerans. Eastern Siberia seems to be a transitional zone between “European-Western Siberian” and “Beringian” faunistic complexes. Our studies will be continued applying genetic methods (i.e. a routine barcoding). The study is supported by the Russian Foundation for Basic Research (grants 12-04-31556 and 12-04-00207) and the Program "Biodiversity: State and Dynamics".