Cladocera (Crustacea: Branchiopoda) of Cat Tien National Park, South Vietnam

Cladocera of Cat Tien National Park, South Vietnam, and the surrounding agricultural area, were surveyed during the spring of 2009 (onset of the wet season) and autumn 2010 (end of the wet season). The studied water bodies included two large lakes (Bau Sau and Bau Chim), small lakes and ponds, temporary pools, rivers and streams, as well as rice fields and ponds in an agricultural area beyond the boundaries of the National Park. Fifty three species of Cladocera were found, 18 of them new for Vietnam. Distribution and taxonomical status of the species are discussed. Of the recorded species, 58.5% (31) were found only in the National Park, 34% (18) both in the National Park and the agricultural area, and only 7.5% (4) exclusively in the agricultural area. Of the 20 species new for Vietnam, only one was found both in the National Park and the agricultural area, all others were found in the National Park only. Such a difference can be directly attributed to the loss of natural habitats (forest ponds and streams) in agricultural areas and to the pollution by pesticides. Our study shows the importance of surveys in pristine and protected areas, for the full evaluation of regional microcrustacean richness.