Finless porpoise inhabits most of the areas or water of the Korean peninsula, Jiuduansha, and the Yellow and East China seas. They fall under the family Phocoenidae with the most distinct characteristic being lack of a true dorsal fin. These animals have an unusually steeper forehead, moderately large flippers, and bodies in uniform bright grey color. Compared to other porpoises, they are rarely social, prefer solitary or small schools, less energetic, and less showy, but can show tail stands and acts of breaching. Finless porpoises also prefer coastal waters, putting them at risk of death from human activity and entanglement in gill nets.