Ponto-caspian
Guides
Onychopoda
Onychopoda is a specialized order of predatory branchiopod crustaceans within the superorder Cladocera, distinguished by having only four pairs of legs (compared to five or six in related orders) and segmented raptorial appendages used for grasping prey. The order comprises three families (Cercopagididae, Podonidae, Polyphemidae), ten genera, and approximately 33 described species. Most species are endemic to the Ponto-Caspian basin, though some occur in freshwater and marine habitats worldwide. Onychopoda exhibits one of the most distinctive morphological and ecological radiations among cladocerans, having evolved predation as a novel feeding strategy and colonized habitats across a broad salinity range.