Ocean Sunfish
Mola mola
One of the oddest looking fish you may encounter during one of our whale watching trips is the Ocean sunfish or “Mola mola” (which is actually their latin name). Ocean sunfish are the largest bony fish in the world (some shark species are larger but have skeletons made of cartilage, not bone) and can be 10.5 feet long and weigh over 5,000 pounds. The typical Ocean sunfish, however, is usually around 6 feet long and weighs about 1,000 pounds.
Quick Facts & Stats
Heaviest bony fish
Flattened, disk-shaped body
Tiny mouth, big body
Often sunbathes surface
What makes Ocean sunfish so strange looking is that they don’t have the typical fish shape… at least not as adults. When Ocean sunfish first hatch the “fry” are shaped like a typical fish, infact the Ocean sunfish fry look a lot like miniature Puffer Fish to which they are closely related. As they mature, however, the tail fin disappears and the dorsal and anal fins merge to create one large, lobed structure called the “clavus.” This gives the Ocean sunfish the appearance of being a fish which has been cut in half. The lack of a true tail means that they are not the quickest or most agile swimmers, and many individuals show scars from having hit by boats or having a bite taken out of them by a shark of some kind.
Ocean sunfish get their name because they are frequently seen swimming on their sides at the surface on hot Summer days and appear to be sunning themselves. They are actually feeding, however, and their diet is made up almost exclusively of jellyfish. Their pectoral or side fins can often be seen sticking up out of the water and can look a lot like the dorsal fin of a shark.
Ocean sunfish prefer warmer waters of 50 degrees F or greater and thus we usually don’t start seeing them until the end of the Spring when the water has had a chance to warm up a bit.
