Clownfish What is a Clownfish?

Clownfish come in a wide variety of colours and usually have vertical bands across their bodies. These fish were given the name 'clown fish' because of their bright colours and their very active behaviour which appears as though they are 'clowning around'. Clownfish are also referred to as anemonefish because they make their home only amongst sea anemones whose poisonous tentacles offer them protection from predators.

Scientific name: Amphiprioninae

What Type of Clownfish is Nemo? Nemo's Species

The clownfish, with its distinctive orange with white stripes, depicted in the movies Finding Nemo and Finding Dory were ocellaris clownfish (Amphiprion ocellaris), also known as the false percula clownfish or common clownfish. These fish are found on the Great Barrier Reef.

Clownfish - Description & Characteristics What Does a Clownfish Look Like?

There are 28 species of clownfish, and they come in a variety of colours such as orange, red, pink, yellow, black, and brown. They may have 0-3 stripes of different colours running vertically around their bodies. They are small fish with rounded fins. Depending on the species they can grow to 9-11cm in length.

All Clownfish are Born Male

Clownfish are hermaphrodites. They are all born male but can change into females as required. While males can morph into females, this process is irreversible. That is a female cannot revert back to a male.

The dominant fish in the group, usually the largest, will always be female. The second most dominant will be a male, and her breeding partner. All other members of the group will remain male. If this dominant female dies, then the next most dominant member of the group, in this case, her former partner the dominant male, will morph into a female. And the next most dominant member of the group will become her breeding partner. This dominant male will keep other males from growing large by preventing them from getting sufficient food.


Clownfish - Habitat & Distribution Where Do Clownfish Live?

Clownfish live in the Great Barrier Reef off the north-eastern coast of Australia and in Southeast Asia. They make their homes in certain types of sea anemone found in the shallower waters where there is ample sunlight.

A single familial group of clownfish may occupy a sea anemone and always stay in very close proximity to it. They are fiercely territorial and will vigorously defend their home, the sea anemone, against other clownfish and predators.

Sea Anemone — Home of the Clownfish

Relationship between the Clownfish and Sea Anemone Mutual Symbiosis

The clownfish and its host, its sea anemone, live in a mutually beneficial symbiotic relationship. The sea anemone provides the clownfish with a home and protection, and the clownfish, in turn, provides the sea anemone a number of services. This relationship is called mutualism because both parties gain a benefit from their cooperation. There is no evidence to suggest that the sea anemone definitely needs the clownfish or that the clownfish needs the sea anemone for survival. They have just figured out that life is much better when they both help each other.

Clownfish Acts as Bait for the Sea Anemone

The small colourful clownfish attracts predators towards itself as its darts in and out of the sea anemone's tentacles. When the predator comes close to investigate, the sea anemone springs into action and captures and consumes the predator.

Clownfish Feeds the Sea Anemone

A clownfish may catch bits of food too large for it to consume itself and feed this to the sea anemone. There are even reports that it may capture prey, such as a shrimp, and drag it into the grasping tentacles of a waiting sea anemone.

Clownfish Scavenges and Cleans and Gets a Free Meal

The sea anemone ejects much uneaten material. The clownfish happily eat this food debris effectively cleaning house for the sea anemone and getting a free meal in exchange for its cleaning services. The clownfish also perform other maintenance services such as removing dead tentacles.

Clownfish Defended the Sea Anemone

The clownfish being very territorial and aggressive will defend its home from predators, such as butterfly-fish, that are likely to harm its host sea anemone.

Other Maintenance Services

The clownfish darting in and out of the sea anemone's tentacles serves a useful purpose of aerating the water between the sea anemone’s tentacles but more importantly, this constant movement also dislodges debris which may be lodged between its tentacles.

How Clownfish Survive the Sea Anemone's Tentacles Why are Clownfish Immune to Anemone?

Although the sea anemone paralyses and kills fish that touches it, it does not harm the clownfish. The clownfish, it seems, is immune to the sea anemone's poison. The clownfish attains this immunity because of a thick layer of mucus that covers its entire body. This mucus layer is three to four times thicker than on other similar fish and bears a very close resemblance to the sea anemone’s own mucus chemistry.

One theory is that a young clownfish builds up immunity by gently brushing against the sea anemone and being stung mildly. This causes the clownfish’s body to secrete a special soothing, protective mucous as a reaction to this. In the process, it is possible that some of the sea anemone’s mucous acquired with the sting is incorporated into the clownfish’s mucous better helping it mimic the sea anemone’s own mucus chemistry. The clownfish now covered in its protective mucus amour, does not trigger the nematocyst discharge response in the sea anemone. It can then swim through the tentacles of the sea anemone with ease, living in a well-armed fortress protected against predators.

Clownfish - Diet What Do a Clownfish Eat?

Clownfish are omnivorous, eating both animal and plant matter. Besides eating any leftovers from the sea anemone's meals and the dead tentacles of their sea anemone host, clownfish also eat plankton, mollusc, zooplankton, phytoplankton, small crustaceans, and various algae.

Clownfish - Reproduction Clownfish Babies

Clownfish in the more tropical waters of the Great Barrier Reef spawn all year round and seem to be linked to the lunar cycle. At this time the male attracts the female by courting her by dancing in front of her, biting and extending his fins. The male then readies a patch of rock at the base of their host sea anemone. Spawning begins when the female swims over the patch cleaned for her by the male and deposits 100 to 1000 eggs. The male follows her and fertilises them. The female will then return to take care of the sea anemone while the male stays behind to guard the eggs until they hatch. He will remove debris and dead eggs and fan the eggs with his fins and mouth to keep them well oxygenated. The eggs will hatch in 6 to 7 days and the juvenile clownfish will remain in the vicinity for a few more days until they develop the protective mucous coating necessary for them to venture into the sea anemone.

Clownfish live for between 6 to 10 years.

Clownfish Threats & Predators What Dangers do Clownfish Face?

Even though clownfish are reasonably well protected by their sea anemone host the do fall prey to large fish especially sharks and eels. One of the most insidious threats to these fish come from humans who capture them to keep as pets in tanks and aquariums. Presently they are one of the most popular aquarium fishes.

Conservation Status Is the Clownfish Endangered?

The clownfish is not considered to be endangered.