【How-to】Are crayfish vertebrates - Howto.org

Crustaceans (Crustacea /krʌˈsteɪʃə/) form a large, diverse arthropod taxon which includes such animals as crabs, lobsters, crayfish, shrimp, krill, prawns, woodlice, barnacles, copepods, amphipods and mantis shrimp. … Like other arthropods, crustaceans have an exoskeleton, which they moult to grow.