Mola mola: Strange fish spotted off Hampton Beach

Mola mola, I love that name. As Latin names go I think it is exactly right for the ocean sunfish.

Recently ocean sunfish have been sighted about 10 miles southeast off Hampton Beach. They have been sighted by the commercial fishermen and local whale watch boats. I don’t believe there is a stranger fish swimming through our waters.

My first encounter with an ocean sunfish, I couldn’t believe my eyes. Their dorsal fin (top) is large, pointed and flops around on top of the water like a limp shark fin. They appear to be made of a black rubbery material with no noticeable scales. Sunfish have a mouth that is tiny and pointed with a huge rounded head but the strangest part of this fish is its lack of a normal tailfin. They look like a huge fish that has had its back end hacked off.

How they swim is a mystery to me. Most of the time they appear to flop back and forth in the water as if they are half dead, but like most creatures they can become extremely animated when mating. My husband was witness to a mating ritual that appeared to defy gravity. He saw two ocean sunfish flopping side by side for several minutes and was astounded when one jumped straight up about 5 feet and belly-flopped causing an enormous wake. These two fish continued jumping for about 10 minutes and then lay motionless as if they were dead. He couldn’t believe that a fish with no tail fin had managed to jump that high!

Not a lot is known about the fishes life cycle. The young are equally strange looking with huge spines protruding from their body. These spines are absorbed by the skin carapace which develops in the adult fish. It is a mystery where they lay eggs or even where they hatch. They prefer temperatures of 50 degrees or warmer and become lethargic and even hypothermic when in colder water for extended periods.

They are a huge fish averaging in size from 3-5 feet and 6 feet from the tip of the dorsal fin to pelvic fin, appearing throughout the Gulf of Maine in the summer feeding on ctenophores, jellyfish, salps and other soft-bodied animals. They can sometimes be seen along the beaches of Plum Island feeding. Their only real predators are sharks and possibly seals probably because of their hard rubbery exterior and the fact that they have a layer of glutinous fat just below the skin and not much real meat.

If you have a chance to see this animal, I guarantee your first impression will be complete astonishment then awe. They appear as if from a primordial sea, a leftover remnant from the age of dinosaurs and megalodons!

Goethel is a marine biologist and the owner of the Explore the World Oceanarium at the Hampton Beach.