The term "sunfish" generally refers to the ocean sunfish, although there are also freshwater sunfish species. Ocean sunfish live in tropical and temperate waters in the Indian, Atlantic and Pacific Oceans, as well as the Mediterranean Sea. They feed on jellyfish, crustaceans, mollusks and zooplankton. They have an average lifespan of 10 years in captivity, but their lifespan in the wild is unknown.
Scientific & Common Names
Kingdom - Animalia
Phylum - Chordata
Class - Actinopterygii
Order - Tetraodontiformes
Family - Molidae
Genus - Mola
Species - M. mola
Common Name - Ocean Sunfish, Sunfish, Mola, Common Mola. Should not be confused with the several species of freshwater sunfish, Genus Lepomis, which are not closely related..
Ocean sunfish have rough, rubbery skin that is typically a silvery hue, although their bellies are white. They have an oval body shape due to their tail fin, which folds up rather than growing. They have large dorsal fins that resemble those of sharks, and their teeth grow into a beak-like formation. Adult ocean sunfish measure around 11 feet long and weigh up to 5,000 pounds, making them the largest species of bony fish.
Scientists do not know much about the breeding of ocean sunfish. They do know that females are capable of producing more than 300 million eggs at a time, although the time it takes for the eggs to hatch and the amount of parental care involved are not known.
Sunfish larvae are less than three millimeters long. These in turn become "fry" or baby fish. Sunfish fry are covered in spines like their close relatives the pufferfish, although they lose these spines as they grow.
Ocean sunfish swim slowly and use their truncated tail fin to propel their bodies through the water. They are able to jump above the surface of the water up to 10 feet and splash onto the surface in order to remove skin parasites. Ocean sunfish also allow birds and smaller fish to eat these parasites when they are still on their skin. They are generally solitary, but they do gather in groups when they let other fish clean their skin. They sometimes bask close to the water's surface. They feed primarily on jellyfish.
A few ocean sunfish have been kept in aquariums and other marine parks since 1941, but they are hard to care for in captivity due to their size. Their awkward movements put them at risk of hurting themselves by hitting the sides of their tanks.
Ocean sunfish do not have an official conservation status, but their populations are believed to be stable. They do face threats from marine debris and gill nets. They are also caught by humans for food and for use in traditional Chinese medicine.