into a number of major groups - the branchiopods, the maxillopods, the ostracods and the malacostraca. the malacostraca are further divided into five groups - decapods (e.g. crabs, lobsters and shrimp), stomatopods (mantis shrimp), euphausiids (krill), amphipods (e.g. sandhoppers) and isopods (land-based...