Research topic: crustacean

crustacean , primarily aquatic arthropod of the subphylum Crustacea. Most of the 44,000 crustacean species are marine, but there are many freshwater forms. The few groups that inhabit terrestrial areas have not been particularly successful in an evolutionary sense; most require very humid environments in order to survive. Types of Crustaceans Crustaceans can be divided according to size into two main groups. The larger group, which is divided into the classes Branchiopoda, Copepoda, Ostracoda, and Cirripedia, includes the familiar shrimp , crayfish , lobsters , and crabs . The... Read more