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The clownfish, and if you adopted a Nemo?

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The term “clownfish” commonly refers to two well-known species of amphiprions: the Pacific clownfish (Amphiprion percula) and the three-band clownfish (Amphiprion ocellaris). In everyday language, all species in the Amphiprion category are often referred to as clownfish. These are saltwater fish species endemic to the Pacific Ocean and the Indian Ocean, and they are currently not endangered.

Appearance of Clownfish

Clownfish, or amphiprions, typically measure between 2.76 inches and 5.91 inches in length. The length-to-width ratio of these fish can reach up to 2.5. Depending on the species, clownfish can be black, orange, yellow, or red. Some even have spots or stripes.

The three-band clownfish (Amphiprion ocellaris) is recognizable by its bright orange color and three vertical white bands. The middle band has a protrusion towards the fish’s head. The Pacific clownfish (Amphiprion percula) is recognizable by the thin black lines that border the three white bands on its body. Both species of clownfish have fins bordered in black. There are also black-colored three-band clownfish.


Sex and Reproduction

Clownfish have a unique characteristic regarding their sex and reproduction. They are all born male and can later change to become females at an advanced age. These fish species live in schools, with the oldest and highest-ranking clownfish being the female at the head of the school. The second oldest and highest-ranking clownfish is the male breeder. If the female dies, the oldest male takes her place and becomes female, and the second oldest male becomes the new male breeder.

Types of Amphiprions

Amphiprions belong to the Pomacentridae family and are divided into 29 distinct species, grouped into 5 categories (Actinicola, Amphiprion clarkii, Amphiprion ephippium, Paramphiprion, Phalerebus). The most well-known species of amphiprions are the clownfish (Amphiprion percula and Amphiprion ocellaris), which gained popularity through the movie “Finding Nemo.”

Other species of amphiprions are also highly appreciated in the aquarium hobby, such as the saddleback clownfish (Amphiprion ephippium), measuring approximately 12 cm in length and featuring a black spot on its flank and a white band on its head. The two-band clownfish (Amphiprion bicinctus), in shades of orange and brown, measuring around 3.94 inches, is also popular among aquarium enthusiasts. This species is endemic to the Red Sea.

Natural Habitat of Clownfish

Clownfish are found in tropical regions such as the Indo-Pacific basin, influenced by warm currents from the north or south, for example, off the coasts of Australia, China, Japan, Indonesia, Taiwan, Thailand, India, Malaysia, and the Philippines. The region of Papua New Guinea is the richest in clownfish species, with about ten species around Madang and eight species on Entrecasteaux Island. In other regions, such as Guam in the western Pacific or near Lizard Island in the Great Barrier Reef, five species are recorded. Two species are found in the Red Sea, and only one species is found in the Comoros. Clownfish are no longer found on the coasts of Hawaii.

The distribution areas of the Pacific clownfish and the three-band clownfish are distinct. While the Pacific clownfish swims off the coast of Papua New Guinea, the three-band clownfish occurs in the waters of the western Pacific and northern Australia.

Symbiotic Relationship with Sea Anemones

Clownfish have a unique symbiotic relationship with sea anemones. Different species of clownfish live in harmony with specific species of sea anemones. While many fish species avoid anemones, the mucus of clownfish protects them from the toxins of these marine animals. It is still difficult to explain how the protective mucus layer develops in clownfish, but it is certain that the fish does not produce it. Some species of clownfish require an acclimation period to gradually adapt to the venomous anemone, while others can enter without any problems.

By hiding within the sea anemone, clownfish protect themselves from their predators, such as butterflyfish (Chaetodontidae) and filefish (Monacanthidae). The sea anemone benefits from improved water circulation due to the clownfish’s activity. Moreover, the dead tentacles of the anemones and their leftover food serve as a food source for the clownfish. The colorful clownfish attract their predators into the anemone’s tentacles, which then consume the trapped fish. Clownfish also fertilize the anemones with their waste. These colorful fish follow the principle of polyandry, with one female surrounded by multiple males living in one or more different sea anemones. The symbiosis between clownfish and sea anemones typically lasts for several years.

Feeding Clownfish in an Aquarium

Clownfish are omnivorous fish. In their natural habitat, they feed on plants such as algae and copepods, as well as shrimp and plankton. In an aquarium, it is important to provide varied, balanced, vitamin-rich food of both plant and animal origin for the clownfish. Since clownfish never venture far from their sea anemone to hunt and instead wait for prey to come to them, they tend to store excess food. This behavior is natural. Monitor this behavior in your aquarium’s clownfish.

Keeping Clownfish in an Aquarium: Tips

It is important to note that keeping sea anemones in an aquarium, as suggested in the movie “Finding Nemo,” is difficult. Sea anemone cultivation is more suitable for experienced individuals familiar with the peculiarities of saltwater aquariums.

Clownfish are schooling fish and should never be kept alone. Ideally, they should coexist with conspecifics, either in pairs in a small aquarium or in groups in a larger aquarium.

Due to the interdependent relationship between clownfish and sea anemones, one of the following three anemone species should be included in your saltwater aquarium: magnificent anemone (Heteractis magnifica), giant anemone (Stichodactyla gigantea), or Mertens’ anemone (Stichodactyla mertensii). Sea anemones can also survive without clownfish, but the reverse is not possible. Clownfish absolutely need their sea anemone, although certain species of clownfish are only compatible with specific species of sea anemones.

Coral sand makes a suitable substrate for clownfish aquariums. However, introducing live corals should be avoided, as the constant movement of anemones within the aquarium could cause serious injuries or burns to the corals.

Sea anemones are relatively sensitive species. To prevent them from moving excessively, pay special attention to brightness (which should be intense), current (weak and indirect), nitrate and phosphate levels (which should be low), and oxygen levels (which should be high) in your aquarium. If your anemones are healthy, you have the essential condition for the well-being of your clownfish. It is also recommended to regularly test the water in your aquarium.

It is important to ensure that the size of the sea anemone is appropriate for the number and size of the fish in your aquarium. If the anemone is too small, it may deteriorate due to an excessive number of fish. Conflicts can also arise between clownfish.

The three-band clownfish generally exhibit peaceful behavior towards other fish, but conflicts can still occur with other species of clownfish. If you want to keep more fish together, opt for a larger aquarium.

Water Temperature and Aquarium Size

The aquarium for clownfish and sea anemones should have a capacity of around 200 liters. Although clownfish are poor swimmers that rarely stray from their sea anemone, the anemones still need sufficient space.

The ideal water temperature should be between 73.4 and 82.4°F to match the temperatures of tropical waters. The pH should range from 8.0 to 8.4, and the hardness should be between 0 and 32 °dH (degree of hardness). It is imperative to have a saltwater aquarium, which means the aquarium water must be salty and cleaned using a reverse osmosis system. Clownfish and sea anemones should never be kept in freshwater.


Can You Keep Clownfish in an Aquarium?

Clownfish are among the few marine fish that can be kept in an aquarium. During their courtship, male clownfish perform a dance for the female. The male then cleans the breeding site at the base of the sea anemone (which can be a flat rock, for example). This is where the female lays her eggs, which the male then fertilizes. During the first day, the eggs are yellow-orange in color. From the third day onward, they become brownish and gradually lighter or even transparent until hatching day. The male plays an essential role by fanning the eggs with its fins to keep them in fresh and oxygen-rich water.

After about a week, the eggs hatch. During the first few days, clownfish larvae are planktonic organisms. This larval stage lasts for about 2 weeks, during which the larvae are well protected at the base of the sea anemone. Afterward, the young clownfish search for their own sea anemone. From the 12th day, freshly hatched brine shrimp larvae and powdered phytoplankton are suitable food for the clownfish larvae.

Life Expectancy of Clownfish

In the ocean, clownfish can live up to ten years. However, in an aquarium, their life expectancy is estimated to be around five years. These fish are not particularly fragile as long as they live in a well-maintained saltwater aquarium and the essential conditions for their well-being, mentioned above, are met. Since clownfish must coexist with sea anemones, which are vulnerable and require significant attention, having clownfish at home is more suitable for experienced aquarium hobbyists. This is also due to the fact that a saltwater aquarium is necessary, which may not be ideal as a first aquarium due to the financial expense and experience required for its proper operation.

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- Mahatma Gandhi

“The greatness of a nation and its moral progress can be judged by the way its animals are treated.”

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