Amphiprion ocellaris

KINGDOM: Animalia (Animals)

PHYLUM: Chordata (Possessing a notochord)

CLASS: Actinopterygii (Ray-finned fishes)

ORDER: Perciformes (Perch-like fish)

FAMILY: Pomacentridae (Damselfishes and clownfishes)

SUB-FAMILY: Amphiprioninae (Clownfish)

GENUS: Amphiprion (Clownfish)

SPECIES: Amphiprion ocellaris (Common clownfish)

Distribution

The Common clownfish is native to the Indo-West Pacific, from Northwest Australia to Southeast Asia, and as far north as the Ryukyu Islands of Japan

Common clownfish are small fish (reaching a length of about 11cm) that are an orange to red-brown colour, with three vertical white bands on the head and body. The white bands have thin black outlines. There is also a thin black line around the tips of each fin. The tail fin (caudal fin) is rounded and females are larger than males.

Common clownfish prefer shallow water coral reefs, outer reefs and shallow lagoons. They can be found living amongst the venomous tentacles of anemones. The tentacles of the anemones normally sting other fish, but clownfish excrete a mucus over their skin that tricks the anemone into believing it is touching itself, so it does not sting.

Common clownfish are omnivores (eating almost anything nutricious). They feed on equal amounts of algae and animals and will eat zooplankton, copepods, algae as well as parasites from their anemone.

Clownfish live in groups (called schools) that guard their host anemone against other clownfish. There is a strong hierarchy within the school and the largest female is dominant. These clownfish are highly territorial.

Common clownfish are monogamous (having one mate at a time). Only the largest male will mate with the dominant female. Courtship rituals include chasing, biting and extending the fins. Males prepare a nest of clear substrate on bare rock that is close enough to the anemone to still ensure protection for the eggs. The female clownfish lays between 100 and 1000 eggs which are fertilised by the male. The eggs will be guarded and protected by the male until they hatch after 4-5 days.

Once hatched, the young clownfish spend about two weeks floating in the open sea, before settling on a coral reef and finding a host anemone. Hatched baby clownfish are independent. Sexual maturity is reached at about 18-24 months. They can live up to about 10 years.

Common clownfish exhibit a phenomenon known as ‘protandrous hermaphrorditism’ where all clownfish are born as males, but also have dormant female reproductive organs. If the dominant female were to die or get removed from the group, the largest male turns into a female. A new male will become the dominant male.

Common clownfish don’t have many predators due to their relationship with the anemone. Eggs may be eaten by other damselfish and wrasses.

The greatest threat to the common clownfish is global climate change, which threatens this species through a combination of habitat loss, disruption of its senses and direct effects on its behaviour.
Did you know?

Clownfish are the only fish known to be able to live amongst the tentacles of anemones

Clownfish communicate by making popping and clicking noises

Almost all fertilized eggs of clownfish will hatch and reach adulthood. Because of that, number of clownfish is high and their population is stable

The main character in the 2003 animated film Finding Nemo, was a clownfish

DID YOU KNOW?

Elephant seal

Elephant Seals can hold their breath for up TWO HOURS! But how? Well, seals have more blood in their bodies than any other animal and, since oxygen is stored and carried around the body in blood, it allows them to hold their breath for an extra long time.