The ocean sunfish, Mola mola, is the heaviest known bony fish in the world, it can grow to an average weight of 1,000kg. These fish are ocean travelers and can be found in both tropical and temperate waters around the world. The are a strange looking fish and sometime appear to be as broad and they are long almost disk shape. The German name for this fish is “Schwimmender Kopf” meaning swimming head, which gives you some idea of what Mola Mola look like. They live mainly on Jellyfish, consuming large quantities of them to develop and maintain their large bulk. Juveniles resemble purrerfish, 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, orcas and sharks will eat them. Sunfish are considered a delicacy in some parts of the world, including Japan, Korea and Taiwan. In the EU, regulations ban the sale of fish and fishery products[ derived of the Molidae family. Sunfish are frequently, though accidentally, caught in gillnets.