Branchiopoda

Branchiopoda is a class of crustaceans. It is the sister group to the other crustaceans. They are mostly small, freshwater animals that feed on plankton and detritus. However, many of the Cladocera are marine.
Branchiopods have gills on most of the animals' appendages, including some of the mouthparts. The name means "gill-foot".