Ocean Sunfish Oddities

It’s always a bit strange when you cross tacks with an ocean sunfish. They look like the most uncoordinated klutzes in the seas, and the first glimpse of a large fin makes one think of a whale or shark. But as a slow-motion convergence unfolds, their inability to move out of the way reveals a clumsy fish, making you wonder why the species hasn’t succumbed to the Darwin awards. We recently had this experience while sailing near shore on the coast of Maine.

On a sunny afternoon sail in about 80 feet of water in Harpswell Sound, Maine, a fin popped up in front of us but never moved. We quickly passed what must be the slowest moving fish in the sea. Ocean sunfish are typically found in temperate waters and can grow to 2,000 pounds on a primarily jellyfish diet. Given their ability to swim, the jellyfish is the perfect prey.  

Despite their apparent poor swimming abilities, they are known to dive to depths of 2,000 feet, can propel themselves at up to two miles per hour, and can cover 16 miles in a day. Amazingly, they have also been known to leap out of the water when being pursued by a predator. What might have outfoxed evolution is the fact that female ocean sunfish produce more eggs than any other known vertebrates, and can release up to 300,000,000 eggs at a time! All those eggs must be to help compensate for the difficult-to-envision role of the male ocean sunfish.

When mid-ocean, they’re a friendly neighbor and appear to be one of the most relaxed and contented fish in the sea. When we ran into one, we were sailing along at a leisurely four knots so only about twice the speed of an ocean sunfish at full throttle. We made a couple of passes to say hello as the sunfish gave a wink and hoped another jellyfish would drift in front of its waiting mouth.