Starfish are echinoderms. Starfish are mainly distributed in shallow seabed sand or rocks all over the world. The ocean is a greedy carnivore. Starfish include starfish and petrels. There is obvious separation between each wrist and the middle plate of the seagoing ship, but there is no separation between each wrist and the middle plate of Haiyan. From a professional point of view, the name starfish is the name of a class, and starfish and petrel are the names of species.