Clownfish Facts: They Eat Their Own Eggs as a way of Protection

Clownfish, or anemonefish, are one of the more popular fish in the tropical reef aquarium. You may know these fish through the Finding Nemo film. They are cute, colorful, and special. One of the most interesting things about the species is that they can change gender. Let’s find out 9 interesting facts about clownfish!

Scientific name: Amphiprioninae
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes

1. There are 30 clownfish species

The clownfish is a member of Pomacentridae family. They are tiny saltwater fish with an average size of 4 inches in length. The smallest one is about 2.5 – 3 inches (7 to 8cm), while the biggest one is about 7 inches (17cm). There are about 30 different types of clownfish with different colors and features. Those fish are divided into 2 genera: Amphiprion and Premnas.

You may find the clownfish’s look through the Nemo character in Finding Nemo animated film. However, anemonefish do not only come with orange backgrounds with white bands. They have a wide range of hues, from red, and blue, to yellow to white with dots.

A common clownfish si swimming

Although their coloration and markings frequently indicate the subspecies, all of these types are still categorized as clownfish. The Clarks anemonefish and the Ocellaris clownfish are the two most well-known anemonefish.

Clarks anemonefish (clarkii) are also known as yellowtail clownfish. They have a robust body and an oval to rounded shape. They’re colorful with black and yellowish color and white stripes. The particular pattern, however, differs widely from area to area.

The Ocellaris clownfish (amphiprion ocellaris) is the cute Nemo clownfish that you usually see on TV. This species is also called the common clownfish or the false percula clownfish. It has an orange body with white bands.

They are frequently mistaken for the orange clownfish which is characterized by the black border around its three white stripes.

This is the rarest anemonefish
McCulloch’s anemonefish

This species is so popular that people breed them to create multiple morphs like the snowflake, gladiator, misbar, mocha, chocolate, black snowflake, midnight, bullet hole, snow storm, black storm, and black ocellaris clownfish aka black darwin (have zombie and domino version), etc.

The other anemonefish species are:

– True percula clownfish: aka the orange, the picasso clownfish. They have some morphs like platinum, blizzard, onyx, nebula, etc.

– Cinnamon clownfish: aka red and black anemonefish, dusky anemonefish, fire clownfish, or black-backed anemonefish.

– Maroon clownfish: aka spine-cheeked anemonefish. There are many captive-bred morphs of this anemonefish type, such as gold stripe maroon, lightning maroon, goldflake maroon, thunder maroon, peacekeeper maroon. Those morphs are called designer clownfish.

– Tomato clownfish: aka bridled anemonefish, red tomato clown, blackback anemonefish, and fire clown. This type of fish is very selective. They only host bubble-tip anemones.

– Whitetail damselfish: aka black and white damselfish, humbug damselfish, or three-stripe damselfish.

– McCulloch’s anemonefish: aka whitesnout anemonefish or Amphiprion mccullochi. This is the rarest clownfish.

The other species are pink skunk, saddleback, red sea, sebae, orange skunk, Australian, etc.

People even breed between different species to create new types, such as black ice, frostbite, mocha storm, orange storm, davinci, flurry, black photon, blood orange, blue stripe, snow onyx, super storm, etc.

2. They’re found in warm waters

Anemone fish don’t live in the Atlantic Ocean, the Mediterranean, or the Caribbean Sea. Their natural habitats are in warm waters, like the Pacific Ocean and the Red Sea. They are also found in the coral reefs in the Indian Ocean, and off the coasts of Japan and Australia.

The Indian Ocean is the most common place to encounter this fish. To stay warm throughout the winter, they will travel to deeper water. To observe anemonefish at any time of the year, you can go to the reefs surrounding Green Island, Heron Island, Magnetic Island, Whitsunday Islands, and Lady Musgrave Island.

Anemonefish are parts of the Great Barrier Reef’s “Great Eight.” It includes giant cod, turtles, potato cod, whales, Maori wrasse, manta rays, sharks, and of course, clownfish.

3. Sea anemones and clownfish have symbiotic relationships

Sea anemones are home to all clownfish. This fish species and sea anemones create a symbiotic relationship in which both are beneficial. This is why clownfish are often referred to as anemonefish.

The sea anemones provide home and nest to the fish. They protect themselves from predators and give them leftover food. In exchange, the clownfish get the anemones the prey, eliminate their parasite, and fertilize them with their feces.

In order to establish this type of symbiotic relationship, anemonefish undertake a complex dance with the anemone they want. They use various portions of their bodies to delicately touch the host’s tentacles. To avoid being stung by anemone’s venomous stings, the fish create a protective covering of mucus around themselves.

Not all anemones are suitable for anemonefish. They can only cohabit with only 10 of the approximately 1,000 anemone species. Even yet, only certain couples are compatible. Some popular anemones for clownfish are Stichodactyla mertensii, Heteractis magnifica, and Stichodactyla gigantia. Clownfish cannot thrive without their anemone.

Life is harsh in the ocean, and it’s even harder for the young anemonefish when they can’t acquire a host anemone to live in. They are frequently hunted out by the existing school and forced to seek refuge elsewhere.

4. They’re very social and territorial

Anemonefish are gregarious species. They live in big groups (or schools) of 4 – 6 members. They communicate by using a succession of popping and clicking noises. Those sounds are used to defend as well as to advertise their social status in the school. They create exceptionally close connections with the fish they choose to breed with.

Many people believe that the species are called clownfish solely because of their colors, but this is not true. It is primarily due to their characteristics and behaviors.  

You might think the anemonefish are cute when they jump up and down the anemone. However, looks can be deceiving. They are tenacious, aggressive, and territorial.

To defend their ecosystem as well as their schools, the fish start swimming around wildly, which frequently looks rather foolish. This odd behavior is what gave them their unusual name.



An Artic fox camouflage in the snow

5. They are omnivores

Clownfish are omnivores, which means they eat both plants and other living species. They eat a variety of tiny invertebrates, algae, and leftover foods of anemones. Their diet can include fish eggs, dead anemone tentacles, small crustaceans (shrimp, brine shrimp), worms, phytoplankton, zooplankton, mollusk, and plankton.

To catch the prey, anemonefish will use their vivid colors to draw the prey into the anemones where they are poisoned and consumed. After eating the prey, the anemones leave the scraps for the fish.   

Isopod parasite in the fish’s mouth
Look into an anemonefish’s mouth, you can see a pair of eyes in it. This is an isopod parasite that can adhere itself to the tongue. It takes over the tongue permanently and feeds itself when the fish eats.
It penetrates through the fish’s gills and establishes itself in the mouth using hooklike tentacles. Most anemonefish, according to scientists, can live normally with this parasite.

6. All clownfish are born males

All clownfish are born hermaphrodites. This means that they have sex organs of both genders. However, because the male organs mature faster, the anemonefish develop into males. This makes people think that they are born males. Depending on the environment, the fish can change their sex.

Some of the other Fish that can change gender articles:

In the newly laid group, the biggest fish will become the lone dominant female. It will lead the school. The dominating male will be the second biggest fish. The remaining fish are typically nonbreeding and have immature sex organs.

These creatures have a tight hierarchical structure. The largest female pair and breed with the biggest male. She bullies her partner to keep him from growing too large and changing sexes. On the other hand, the dominant male maintains his status by taking advantage of the best food opportunities.

If the female dies, her mate switches sexes to become the group’s female leader. After turning into females, the fish can’t go turn back. The second biggest male in the group will be the dominant male after his sex organs fully grow.

So, Marlin should’ve switched sexes and become female when Nemo’s mother died. And Nemo should have grown up and become the mate of his previous father.

7. Male clownfish dedicate to their kids

Clownfish are monogamous species. They breed all year, with the female spawning every 10 – 14 days.

Before this, the male prepares the nest, which is normally in their anemone on a near rock shielded by the extending tentacles of a sea anemone. Right before the female deposits her eggs, the male diligently cleans the place.

He spreads his fins and pursues and bites the female. The female then swims over the nesting place several times, laying 100 to 1,000 eggs. After that, the male delivers sperm into the eggs to fertilize them.

After everything is done, the female leaves and the male returns to the nest to look after the eggs. Like emperor penguins, male clownfish are devoted fathers. They stay with the eggs to keep fungus and predators away from them. They make sure that their offspring have enough oxygen by delicately fanning them all the time.

If the eggs are non-viable (not fertilized) and infected with fungus, the males can eat those eggs to protect the others. Inexperienced and young couples, as well as malnourished or undernourished parents, can eat their own eggs. Additionally, the busy, stressful area can make anxious parents devour their eggs too.

The eggs hatch after 8 to 10 days. In contrast to “Finding Nemo,” parents don’t care for the larvae when they hatch. At this time, they will drift away on sea currents.

10 days after floating, if not being eaten, they land on the coral reef’s bottom and find an anemone hosting to stay. During this phase, the juveniles change from transparent to their unique orange color and markings. And they begin a new life cycle.

8. They live longer in the wild

Some species can have a longer lifespan in captivity, some cannot. And the clownfish is one of them. In fact, they tend to have a longer lifespan in nature than in captivity.

The life expectancy of these fish is between 6 to 10 years. A captive one, on the other hand, typically survives for 3 to 6 years. Because of the stress of capturing and transporting, wild-caught clownfish don’t live long.

Following the success of Finding Nemo in 2003, studies suggested that demand for anemonefish in the aquarium market tripled.

9. They are at risks

Because clownfish are not considered critically endangered, they are not included on the IUCN Red List. However, in some locations, their populations have declined. This is due to the fact that they account for 43% of the global marine trade, with 75% of them caught in the ocean.

It is thought that the 2003 film Finding Nemo triggered a boom in demand for these fish for tank pets. The increased fishing of these species may have caused harm to coral reef systems worldwide. Approximately 15% to 30% of the reefs have vanished in this century.

However, many anemonefish in the market are captive-bred.


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