Taxonomic Composition of Zooplankton in the Ubsunur Basin State Nature Reserve (Tyva, East Siberia)

There is analysis of the taxonomic diversity of Rotifers, Copepods, and Cladocerans from water bodies, located on the territory of clusters of the Ubsunurskaya Kotlovina State Natural Biosphere Reserve, located within the Russian part of the Ubsunur Basin, on the border with Mongolia. A total of 87 species from 53 genera, 22 families, 10 orders were recorded. Cladocerans include 40%, Copepods – 37% and Rotifers – 23%. The dependence of species diversity on the level of mineralization was established – 89% were found in fresh water bodies, in salty – 23%, in brackish – 14%. Zooplankton composition of the Lake Tore-Khol has undergone some changes in comparison with the data of the second half of the last century. The zooplankton contains species of crustaceans that are rare for the Rossian fauna – Apocyclops dengizicus, Eucyclops dumonti, Alona flossneri. Tuva is the northernmost point of A. dengizicus in Russia – its habitat, lake Amdaigyn-Khol, located at 530 parallel. The spring Bulak is polluted by mechanized water intake for technical needs, which is confirmed by the appearance of an indicator of this process – Brachionus nilsoni, which then enters the lake Shara-Nur. Location on the shore of the lake Tore-Khol camp site led to the development of Filinia longiseta, which had not previously been observed in large numbers. In general, the presence of rare species for the fauna of Russia in the water bodies of the reserve indicates the presence of favorable conditions for their development and life.

The plankton of Lake Eyre

On the occasion of only its second filling this century, Lake Eyre was sampled seven times between July 1974 (when the minimum salinity value of 7%, was obtained) and April 1975 (salinity 40%,). The dominant zooplanktonic forms recorded were Moina mongolica (first Australian record), Apocyclops dengizicus, Diacypris, Hexarthra fennica and Brachionus plicatilis. It is thought that Daphniopsis pusilla was prevented from obtaining significant numbers because its relatively large size made it vulnerable to fish predation. The most significant phytoplanktonic genera recorded were Nodularia, Anabaenopsis and Glaucocystopsis.