At present, 99 species of cladocerans are known from Thailand, but up to ten more have not been identified to species, particularly in Chydorus, Ephemeroporus and Pleuroxus. Cosmopolitan species are a minority, while wide-ranging circumtropical taxa are an important element, beside species that only occur in the tropics-subtropics of two continents. At least three species are suspected of a neotropical - southeast Asian disjunction, while three more are provisionally considered endemic of Thailand. Daphnia, as usual in the tropics, is rare and reduced to the single D. lumholtzi.