Facts about Ocean sunfish

20 facts about Ocean sunfish

Mola mola

The ocean sunfish is found in all tropical and temperate seas of the world. Its appearance resembles a large head with an attached tail. The body of the animal is flat. When its dorsal and ventral fins are extended, the sunfish is as tall as it is long. It is the world's largest and heaviest bony fish.
They live in temperate and tropical oceanic waters around the globe.
They can be found in all oceans, where the temperature is higher than 10 °C (50 °F). Individuals migrate in hot ocean waters in the summer and may accidentally enter internal bodies of water, however, they die when water temperatures drop.
Ocean sunfish have a very peculiar appearance.
The body is tall, laterally flattened with a crescent-shaped tail that replaced the caudal fin in the course of evolution. Ocean sunfish tail is called clavus. Dorsal and anal fins are elongated and almost vertically oriented. The pectoral fins are relatively small and have a fan-like shape.
The body is covered with thick and elastic skin.
The skin is particularly thick in the abdominal region, where it can be up to 7.3 cm (2,87 in) thick. It is not covered with scales but with mucus and can be very rough, like sandpaper. An exception is a clavus, which has a smooth surface.
Typically adults measure about 1,8 m (5,9 ft) in length and 2,5 (8,2 ft) fin to fin. Weight may vary from 247 to 1000 kg (545 to 2205 lb).
Largest individuals may reach 3,3 m (10,8 ft) in length and 4,2 m (13,8 ft) vertically and weigh up to 2,300 kg (5,070 lb). Research suggests that females may be a bit larger than males.
Colors vary from brown through grey to white.
Different patterns on the skin seem to be determined by the area of occurrence. While endangered or in stress, ocean sunfish can change skin coloration to darker.
They usually live a solitary life.
Mostly they are encountered swimming alone, but pairs also have been spotted. They probably aggregate in more significant numbers during mating season as fertilization takes place in the depths of the water, not on the substrate.
They are slow swimmers.
For many years researchers thought that ocean sunfish moves only by drifting with ocean currents. With some observations, it was noticed that they propel themselves with an average speed of 3,2 km/h. Daily, sunfish can travel up to 26 km (16 mi).
While in danger, they can speed up.
When being pursued, those fish can accelerate rapidly and even jump over the water surface.
They are a predatory species, yet omnivore ones.
They eat a lot of small fish, squids, fish larvae, crustaceans, jellyfish and salps. From time to time, they vary their diet with eelgrass. As their food may lack nutrients, they need to eat a lot.
In search of food, they can dive as deep as 600 m (1 968 ft).
It is estimated that sunfish must eat 1% to 3% of their body mass a day. Foraging takes them usually about half a day. After a long presence in cold depths, ocean sunfish need to bask in the sun.