Ocean Sunfish
The ocean sunfish (Mola mola) is the heaviest bony fish, reaching well over a tonne, with a round, flattened body and no true tail. It drifts through temperate and tropical seas and eats mostly jellyfish.
The ocean sunfish (Mola mola) is the heaviest bony fish, reaching well over a tonne, with a round, flattened body and no true tail. It drifts through temperate and tropical seas and eats mostly jellyfish.
🧬 Field Guide Specimen: Open Ocean Sunfish in the CRV Science Field Guide to log the specimen, see its place among the Vertebrates lineages in the Cladogram Explorer, and test your recall in the Red List conservation game.
A Fish With the Back End Missing
Instead of a tail, the fish has a rounded rudder-like structure (the clavus) formed by fusion of the dorsal and anal fins. Large dorsal and anal fins flap like wings to propel it. It evolved from pufferfish-like ancestors.
Sunbathing and Deep Dives
Sunfish often lie on their side at the surface, which may help them warm up after cold dives to depths of several hundred meters, or let seabirds peck parasites from their skin.
Staggering Fertility
A female can produce hundreds of millions of eggs, the most of any known vertebrate. Despite this, bycatch is a concern, and more than one species of sunfish has been recognized by genetic work.
Ocean Sunfish at a Glance
| Property | Value |
|---|---|
| Scientific name | Mola mola |
| Kingdom | Animalia |
| Phylum | Chordata |
| Class | Actinopterygii |
| Order | Tetraodontiformes |
| Family | Molidae |
| Field Guide group | Marine and Freshwater Fish |
| Diagnostic feature (Field Guide) | Heavily flattened laterally compressed circular body, lacking a true caudal fin, replaced by a rounded clavus rudder. |
| IUCN Red List status | Vulnerable (VU) |
| Family | Molidae |
| Diet | Mainly jellyfish |
See Also
- Moon Jellyfish — typical sunfish prey
- Leatherback Sea Turtle — another jellyfish specialist