is crustacean a class or subphylum
Approximately 30,000 species make up this Subphylum. Most are aquatic; of these, the majority are marine but some are found in fresh water. Members of the Subphylum include lobsters, crabs, crayfish, shrimp, copepods, barnacles, and several other groups of organisms.ost use their maxillae and mandibles to take in food. The walking legs, including specialized chelipeds, may be used to help capture prey. Some crustaceans filter tiny plankton or even bacteria from the water; others are active predators; while still others scavenge nutrients from detritus.