Global diversity and conservation of freshwater crabs (Crustacea: Decapoda: Brachyura)

Abstract

The global diversity of the almost 1400 species of primary brachyuran freshwater crabs that spend their entire lives in freshwater habitats is outlined, along with that of 220 species of secondary brachyuran freshwater crabs that spend part of their life in fresh water and part in salt water. Estimates of freshwater crab diversity based on the current rates of discovery and levels of exploration indicate that the field is still in a growth phase, and it is likely that there are a substantial number of undescribed taxa. The distribution pattern of the brachyuran freshwater crab families across zoogeographic regions is discussed, and the conservation status and current threats to the group are highlighted. It is likely that a greater proportion of the global fauna of freshwater crabs is actually threatened with extinction than is currently realized.