Diet

What does the Oceanic Sunfish eat?

The oceanic sunfish is a carnivore. Their primary food source is jellyfish. Fish, molluscs, plankton and crustaceans are also consumed. Their beak is used to nip off pieces of food.

Due to the low quality of nutrients in jellyfish they must feed on large numbers to sustain them.

Instead of chewing their food they will gradually move it in and out of their mouth which gradually breaks it in to manageable chunks.

Learn more about the Oceanic Sunfish in this video from Data Truck on YouTube

Range

Where do you find the Oceanic Sunfish?

Oceanic sunfish have a wide range which takes in tropical and sub-tropical waters across the globe. Their range extends as far North as the waters off of British Colombia.

They can be found at depths of up to 400m (1312ft) below the surface.

Habitat

Where can the Oceanic Sunfish survive?

These fish live in the ocean primarily being found in pelagic habitats. It is most common to find them at slopes where they can come in to the shallows to find shelter and cleaner fish.

Credit: Public Domain

Reproduction

How does the Oceanic Sunfish produce its young?

Each female may produce as many as 300 million eggs. These are fertilized through broadcast spawning. This is where the male releases sperm at the same time the female releases her eggs.

At hatching the young are just 1cm (0.4in) across and will increase their size 60 million times over during their life. The fry have small spines across their body which help to protect them.

Young known as fry may swim around schools for protection.

While no reliable records of the oceanic sunfishes age at maturity have been produced scientists estimate that it occurs between 5 and 7 years old.

Behavior

What does the Oceanic Sunfish do during its day?

This species is regularly sighted lying on its side at the oceans surface basking in the sunshine.

These animals are solitary. They come together at cleaning stations in small groups.

Previously thought to just cruise on the ocean currents the oceanic sunfish can actually propel itself through the water reaching speeds of up to 3.2km/h (2 miles).

To remove parasites from their skin they will visit cleaner fish stations where small fish eat the parasites for them. When they are floating on the surface some birds may also eat the parasites.

Credit: Yohann Cordelle, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons

Predators and Threats

What stops the Oceanic Sunfish from surviving and thriving?

This species is hunted by orcas, sea lions and large shark species. The California sea lion has been observed biting off a fin and then playing with it rather than eating it.

A range of parasites have been observed attached to the oceanic sunfish. This included barnacles which were found living inside of their throat.

Populations of the oceanic sunfish are believed to be in decline. Most of this data has been recorded through decreases in the presence of this species as bycatch in fisheries.

This species is a regular victim of bycatch. Often there may be more oceanic sunfish in a net than the species which fishers are targeting.

As their favorite food is jellyfish they may consume plastic bags which they confuse for this food source.

While this species is not popular for food some are captured for this purpose. They are also used in some traditional medicines.

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Quick facts

Their scientific name is taken from the Latin word for millstone in reference to the near circular shape of the body.

This species may also be known as the common sunfish, mola or short sunfish.

They were first described for modern science during 1758.

Credit: Nol Aders, modifications by PaladinWhite, CC BY-SA 3.0 <http://creativecommons.org/licenses/by-sa/3.0/>, via Wikimedia Commons