ABSTRACT

Freshwater shrimps of the genus Caridina are the most speciose group within the family Atyidae. This diversity can be witnessed in two ancient lake systems of the Indonesian island Sulawesi, where 21 currently described species, reflect the largest radiations of freshwater shrimps known worldwide. Both lake systems provide similar environmental conditions with locally heterogeneous habitats: Lake Poso is a single lake with less pronounced geographic structure than the Malili lake system with five lakes forming part of the same drainage system. The spatial subdivision in the Malili lakes and the higher number of species compared to Lake Poso (15 vs. 6) renders this system special interest for the study of geographic differentiation.