Streptocephalus Sirindhornae, New Species of Freshwater Fairy Shrimp (Anostraca) from Thailand

Abstract Streptocephalus sirindhornae, new species, the first freshwater anostracan from Thailand, is widespread in the northeast of the country. It is morphologically closest to the Indian species S. dichotomus, but a sequence analysis of its SSU rDNA gene reveals that its closest relative is in fact the Indian species-pair S. dichotomus-S. simplex, that it is probably a conserved member of the S. dichotomus-group, and that it shares some relationship with the S. torvicornis-group.