The ocean sunfish has an unusual shape: an extremely flattened ovoid body, sometimes taller than it is long, or vice versa. Like two large fins with one seemingly upside down, the ocean sunfish has two massive fins: the dorsal fin and the anal fin, both arranged almost symmetrically. Strangely, in the ocean sunfish, the caudal fin is absent and replaced by a kind of 'clothing drape' called the clavus.

The ocean sunfish is a fish of impressive size. On average, it measures about 16 inches in length, but the largest specimens can reach 6.5 to 10 feet long. Its weight matches its bulk, exceeding 2,200 pounds, with a record individual weighing over 5,000 pounds !

Its prominent head features a small mouth. Lacking scales, the ocean sunfish has rough, elastic and very thick skin. Its coloration is silvery gray with whitish patches in some areas.

The ocean sunfish inhabits tropical and temperate waters of seas and oceans worldwide. In the Pacific ocean, it can be found along the coasts of Peru and Chile in the east and along the coasts of Japan and Australia in the west. It is also present in the Atlantic ocean, from Canada to Argentina in the west and from Scandinavia to South Africa in the east. The ocean sunfish is also present in the Mediterranean sea.

The ocean sunfish is a pelagic species that more commonly stays near the seafloor. It is occasionally seen near the surface but prefers deeper waters, down to about 1,640 feet. You are more likely to encounter it from about 130 feet deep or deeper.

Most of the time, you will find it alone, as the ocean sunfish is a solitary species.

The ocean sunfish usually comes closer to the surface to feed on jellyfish, its main food source. It also supplements its diet with fish, crustaceans and mollusks.

The ocean sunfish reproduces sexually. The female releases her eggs in open water, which are immediately fertilized by the male.

The ocean sunfish is listed in the Guinness Book of Records as the world’s heaviest bony fish !

The ocean sunfish is listed as many other marine species within The IUCN Red List of threatened species. The ocean sunfish appears in the IUCN Red List since 2015 within the category Vulnerable !

If you see a fin intermittently breaking the water’s surface, it is probably the dorsal fin of an ocean sunfish swimming on its side near the surface.

Although it is difficult to encounter in open water, the ocean sunfish often reveals its presence by its dorsal fin and the surfacing of its large flank.

However, unless it suddenly appears right next to the boat, it usually vanishes as quickly as it arrived !