Ocean Sunfish (Mola)

The Ocean Sunfish has a distinct, flattened body resembling a giant head with fins. Its body is laterally compressed with a rough, leathery skin texture lacking scales. It possesses large dorsal and anal fins that extend vertically, and a clavus (a rudder-like caudal fin without true rays) at the rear. The mouth is small and beak-like. Coloration typically ranges from silvery-white to grey or brownish. They can grow to immense sizes, making them the heaviest bony fish.

Ocean Sunfish are found in temperate and tropical oceans worldwide. They are pelagic, typically inhabiting the open ocean, but can be seen near the surface in coastal waters for basking or cleaning purposes. They can dive to depths of over 600 meters (2,000 feet) but spend a significant amount of time in epipelagic (surface) waters.

Ocean Sunfish are primarily gelatinous zooplankton feeders, particularly consuming jellyfish, which helps regulate jellyfish populations. They are also known to eat small fish, squid, and crustaceans. Due to their large size, adult sunfish have few natural predators other than orcas, sharks, and sea lions. Juveniles are prey for a wider range of marine predators. They play a role in nutrient cycling as large biomass consumers.

Other species within the Mola genus look similar, such as the Hoodwinker Sunfish (Mola tecta) which was only recently recognized, and the Ocean Sunfish (Mola alexandrini). Distinguishing features between Mola mola and Mola alexandrini often involve body shape, head profile, and features of the clavus. The Sharptail Sunfish (Masturus lanceolatus) has a pointed caudal appendage (clavus extension).