ИСТИНА

Cladocera of Vietnam are poorly studied, only 44 species were recorded in monograph of Than et al. (1980) for North Vietnam, data for South Vietnam is fragmentary. In contrast, Maiphae et al. (2008) lists 99 species for Thailand. We studied cladocera of Cat Tien National Park, Dong Nai Province, South Vietnam. Animalswere collected in April-May 2009 (beginning of wet season) and in September-October 2010 (end of wet season) from more than 50 permanent and temporary water bodies, including two large lakes, forest ponds and streams in protected area, and channels, ponds and rice fields in agricultural are outside of National Park borders. At least 45 species of cladocera were found, including 7 species of Sididae and 27 species of Chydoridae, 9 species were new for Vietnam. Morphology of several poorly known species, including Sarsilatona fernandoi, Camptocercus vietnamensis, Alona cf. quadrangularis, was studied in details. Cladocera form three ecological complexes here – stream species, permanent lakes and ponds species, and species of temporary water bodies and rice fields. These groups are especially distinctive in the spring, while in the autumn they become more mixed die the specimens transport by numerous floods. Beginning of wet season is characterized by dominance of plankton forms, Diaphanosoma, Moinodaphnia and Ceriodaphnia, and low diversity of benthic and littoral forms in most water bodies. Numerous temporary pools were inhabited by abundant Moina cf. micrura. At the end of wet season littoral and benthic forms become dominant, diversity and density of plankton decrease, Moina disappears. Diversity of cladocera within protected area was greater than in agricultural area in both seasons.