Dolphin (Ukrainian: del'fin). Sea mammal of the whale family Delphinidae. The most prevalent species found in the Black Sea is the common or the Black Sea dolphin (Delphinus delphis), which is up to 2.5 m in length and feeds mostly on small fish. In both the Black Sea and the Sea of Azov are found also the common porpoise (Phocoena phocoena), which is 1.5 m long, and the rarer black dolphin or black pig (Tursiops tursio), which is up to 2.5 m long. Dolphins are a valuable hunted species whose fat is melted into oil. Before the Second World War 700,000 to 1,000,000 dolphins were estimated to inhabit the Black Sea, and about 200,000 were killed annually (60,000- 80,000 by the Turks alone). Now their numbers have fallen to 200,000, and since 1966 hunting them has been prohibited by the Soviet government.