Ocean sunfish

Description

The ocean sunfish or common mola (Mola mola) is one of the two heaviest known bony fish in the world, the other being the southern sunfish (Mola alexandrini) of the same genus. Adults typically weigh between 247 and 2,000 kg (545 and 4,409 lb). The species is native to tropical and temperate waters around the world. It resembles a fish head with a tail, and its main body is flattened laterally. Sunfish can be as tall as they are long when their dorsal and ventral fins are extended. Sunfish are generalist predators that consume largely small fishes, fish larvae, squid, and crustaceans. Sea jellies and salps, once thought to be the primary prey of sunfish, make up only 15% of a sunfish's diet. Females of the species can produce more eggs than any other known vertebrate, up to 300,000,000 at a time. Sunfish fry resemble miniature pufferfish, with large pectoral fins, a tail fin, and body spines uncharacteristic of adult sunfish. Adult sunfish are vulnerable to few natural predators, but sea lions, killer whales, and sharks will consume them. Sunfish are considered a delicacy in some parts of the world, including Japan, Korea, and Taiwan. In the European Union, regulations ban the sale of fish and fishery products derived from the family Molidae. Sunfish are frequently caught in gillnets. A member of the order Tetraodontiformes, which also includes pufferfish, porcupinefish, and filefish, the sunfish shares many traits common to members of this order. The ocean sunfish, Mola mola, is the type species of the genus. The caudal fin of the ocean sunfish is replaced by a rounded clavus, creating the body's distinct truncated shape. The body is flattened laterally, giving it a long oval shape when seen head-on. The pectoral fins are small and fan-shaped, while the dorsal fin and the anal fin are lengthened, often making the fish as tall as it is long. Specimens up to 3.3 m (10 ft 10 in) in height have been recorded. The mature ocean sunfish has an average length of 1.8 m (5 ft 11 in) and a fin-to-fin length of 2.5 m (8 ft 2 in). The weight of mature specimens can range from 247 to 1,000 kg (545 to 2,205 lb), but even larger individuals are not unheard of. The maximum size is up to 3.3 m (10 ft 10 in) in length, 4.2 m (13 ft 9 in) across the fins, and up to 2,300 kg (5,070 lb) in mass. The spinal column of M. mola contains fewer vertebrae and is shorter in relation to the body than that of any other fish.