The clownfish, known worldwide as the Nemo fish, captured the hearts of millions with Pixar’s “Finding Nemo” film. With their orange-white striped appearance and unique relationship with anemones, clownfish are the most popular and recognized inhabitants of marine aquariums. Originating from the warm waters of the Indo-Pacific oceans to our home marine aquariums, these fish are fascinating creatures with both their beauty and interesting way of life.
What is a Clownfish (Nemo)?
The clownfish (Amphiprion ocellaris) is a small marine fish belonging to the Pomacentridae family. These fish, scientifically known as Amphiprion, comprise a group of approximately 30 different species. The most common and recognized species is the orange clownfish (Amphiprion ocellaris and Amphiprion percula), which portrayed the character Nemo in the film.
Their natural habitats are the warm, tropical waters of the Indian Ocean, Pacific Ocean, and Red Sea. They live in coral reefs around Australia’s Great Barrier Reef, Indonesia, Philippines, and Malaysia. Clownfish are famous for living in a symbiotic (mutually beneficial) relationship with sea anemones.
Clownfish and Anemone Relationship
The most striking feature of clownfish is their unique relationship with venomous sea anemones. This relationship is one of nature’s most perfect examples of symbiosis.
How Does the Symbiotic Relationship Work?
Sea anemones have arms equipped with venomous stinging cells (nematocysts). These stings are deadly for most fish. However, clownfish are not affected by the anemone’s venom thanks to a special mucus layer covering their bodies. This mucus contains chemical compounds similar to the anemone’s own tissue, causing the anemone to perceive the clownfish as “one of its own.”
Mutual Benefits
Both parties benefit from this relationship. The clownfish is protected from predators among the anemone’s venomous arms and finds a safe home. It also lays its eggs on the anemone and raises its young there.
The anemone gains various benefits from the clownfish. The clownfish cleans the anemone and removes parasites. The fish’s movements provide oxygen to the anemone’s tissues. The clownfish’s food scraps provide a food source for the anemone. Additionally, the clownfish drives away predators that eat anemones, such as butterflyfish.
Which Anemones Do They Live With?
Clownfish don’t live with every anemone species. Of approximately 1,000 anemone species, only 10 host clownfish. The most common pairings include Bubble Tip Anemone (Entacmaea quadricolor), Magnificent Anemone (Heteractis magnifica), Carpet Anemone (Stichodactyla gigantea), and Sebae Anemone (Heteractis crispa).
Clownfish Species
There are approximately 30 different clownfish species in the world. Each has its own unique color and pattern characteristics.
Ocellaris Clownfish (Amphiprion ocellaris)
This is the most common and popular species. The character Nemo in Finding Nemo is this species. It has three white stripes on a bright orange body. The edges of the stripes are bordered with black lines. It is the easiest to care for and most resilient clownfish species.
Percula Clownfish (Amphiprion percula)
Very similar to Ocellaris but has a more intense orange color. The black border lines are thicker. Also known as the “true clownfish.” Slightly more sensitive than Ocellaris.
Maroon Clownfish (Premnas biaculeatus)
The largest clownfish species, growing up to 17 cm (6.7 inches). Has three white or yellow stripes on a dark red or maroon body color. Has a spine on the cheek that other species lack. An aggressive species that displays territorial behavior toward other fish.
Clark’s Clownfish (Amphiprion clarkii)
One of the most resilient clownfish species. Has yellow, orange, or black color variations. Can live with almost all anemone species. Ideal for beginners.
Tomato Clownfish (Amphiprion frenatus)
Has a tomato-red body color. Usually has only one white stripe (at the head region). Medium-sized and semi-aggressive species.
Saddleback Clownfish (Amphiprion polymnus)
Has a saddle-like white patch on its back. Has white markings on a dark brown or black body color. A rare and interesting-looking species.
Pink Skunk Clownfish (Amphiprion perideraion)
Has a white line running from the back to the tail on a pink-orange body color. A gentle and peaceful species. Small in size, growing up to 10 cm (4 inches).
Designer Varieties
In recent years, many special color variations have been developed through selective breeding. Snowflake Clownfish carries unique white patterns. Black Ice Clownfish has a black and white contrasting appearance. Picasso Clownfish contains irregular and artistic white patterns. Platinum Clownfish has an almost entirely white body.
Clownfish Care
Clownfish are among the most resilient and easiest to care for among marine aquarium fish. However, a marine aquarium is more complex and costly than a freshwater aquarium.
Aquarium Requirements
A minimum 100-liter (26-gallon) marine aquarium is required for clownfish care. 100-150 liters (26-40 gallons) is ideal for a pair of clownfish. If an anemone will be added, a 200-liter (53-gallon) or larger aquarium is recommended because anemones can grow and move.
Live rock is important for biological filtration and provides a natural appearance. The aquarium should have a balance of hiding places and swimming area.
Water Parameters
Water parameters are critically important in marine aquariums. Water temperature should be between 24-27°C (75-81°F). Salinity should be maintained between 1.020-1.025 sg. pH should be between 8.1-8.4. Ammonia and nitrite levels should be zero, and nitrate should be kept below 20 ppm.
Marine salt should be mixed with RO/DI (reverse osmosis/deionized) water instead of tap water. Weekly 10-15% water changes are recommended.
Filtration System and Equipment
A protein skimmer is essential for marine aquariums. It removes organic waste from the water surface. A strong biological filtration system is required. Live rock provides natural biological filtration.
A wave maker or circulation pump is important for water circulation. A heater and thermometer are necessary for stable temperature control. If an anemone will be kept, strong lighting (LED or T5) is essential.
Lighting
Medium-intensity lighting is sufficient for clownfish alone. However, if an anemone or coral will be added, high-quality, strong lighting is needed. LED aquarium lighting both saves energy and provides the light spectrum that corals and anemones need. An 8-10 hour light cycle is ideal.
Clownfish Feeding
Clownfish are omnivores and accept various foods. In the wild, they eat zooplankton, small crustaceans, and algae.
Basic Foods
High-quality marine fish pellets or flake foods should be the main food source. Foods formulated for marine fish should be preferred. Feed 2-3 times daily, only as much as they can consume in a few minutes.
Live and Frozen Foods
Frozen small shrimp is one of the clownfish’s favorite foods. Frozen brine shrimp (artemia), bloodworms, and krill can also be given. Live foods stimulate the fish’s natural hunting behaviors and enhance color vibrancy. Frozen or live food supplementation 2-3 times a week is recommended.
Plant-Based Foods
Blue-green algae and seaweed-based foods should also be added to the diet. Nori (seaweed sheets) can be attached to the aquarium with a clip. Plant-based foods support digestive health.
Anemone Feeding
If there is an anemone in the aquarium, the anemone also needs to be fed. Anemones can be fed small pieces of shrimp, fish, or squid 1-2 times a week. Clownfish sometimes carry food to the anemone, which is part of their natural behavior.
How Long Do Clownfish Live?
Clownfish are long-lived fish under proper care conditions. They live an average of 10-15 years in aquarium environments. Well-cared-for individuals can exceed 20 years. They are estimated to live 6-10 years in the wild.
Factors affecting lifespan include water quality, nutrition, stress levels, and genetics. In aquariums with anemones, clownfish are generally less stressed and live longer.
How Big Do Clownfish Get?
Clownfish size varies by species. Ocellaris and Percula species reach 8-11 cm (3-4.3 inches) in length. Maroon clownfish is the largest species and can grow up to 17 cm (6.7 inches). Smaller species like Pink Skunk stay around 10 cm (4 inches).
Females are always larger than males. This size difference is related to the clownfish’s interesting sex-changing characteristic.
Clownfish Sex Change
One of the most interesting features of clownfish is their ability to change sex. This characteristic is known as sequential hermaphroditism.
How Does It Work?
All clownfish are born male. In a group, the most dominant individual transforms into a female and becomes the only female of the group. The second most dominant individual becomes the breeding male. The others remain as sexually immature males.
If the female dies or leaves the group, the dominant male transforms into a female within a few weeks. And the next most dominant individual becomes the breeding male. This transformation is irreversible; once a fish becomes female, it cannot become male again.
Clownfish Breeding
Clownfish are one of the few marine fish species that can be successfully bred in home aquariums.
Pair Formation
When clownfish mate, they stay together for life. The easiest method to form a pair is to get two young fish of different sizes. The larger one becomes female, and the smaller one remains male. Pairing adult fish is more difficult and can cause aggression.
Breeding Behavior
When breeding time approaches, the male cleans the nest (usually a flat surface near the anemone). The female lays 100-1,000 eggs on this surface. The eggs are orange in color and stick to the surface.
The male fertilizes the eggs and protects them throughout the incubation period. He fans, cleans, and removes dead eggs. The female also helps protect the nest, but the main caretaker is the male.
Egg and Fry Care
Eggs hatch in 6-10 days, depending on water temperature. The fry are very small and hatch at night. They feed from their yolk sac for the first few days. Raising fry is difficult and requires special equipment. They should be fed rotifers first, then brine shrimp larvae, and kept in a separate rearing aquarium.
Clownfish Diseases
Clownfish are relatively resilient but can contract certain diseases.
Marine Ich (Cryptocaryon)
Also known as marine white spot disease. White spots on the body, rapid gill movement, and scratching behavior are observed. Copper-based medications or hyposalinity treatment is applied. Treatment should be done in a quarantine aquarium because medications harm anemones and corals.
Brooklynella (Clownfish Disease)
A dangerous parasitic disease specific to clownfish. Symptoms include excessive mucus production, skin peeling, and respiratory difficulty. It progresses very quickly and can kill within 24-48 hours if untreated. Treated with formalin baths.
Marine Velvet (Amyloodinium)
A velvet-like golden-brown dust appears on the body. Similar to marine ich but forms smaller spots and kills faster. Treated with copper or chloroquine.
Fin Rot
Fins deteriorate due to bacterial infection. Poor water quality triggers it. Antibacterial treatment and improvement of water quality are needed.
Disease Prevention
Keeping new fish in quarantine for 4-6 weeks prevents diseases from spreading to the main aquarium. Regular water changes and stable water parameters keep the immune system strong. Quality nutrition also increases resistance to diseases.
Clownfish Tank Mates
Clownfish are generally peaceful but defend their anemones and territories.
Compatible Species
Clownfish are compatible with many peaceful reef fish. Royal Gramma, Firefish, Gobies, Blennies, Cardinal fish, Chromis species, Yellow Tang (in a sufficiently large aquarium), Six-line Wrasse, and small Angelfish make good companions. Cleaner shrimp and other invertebrates are also generally safe.
Species to Avoid
Large and aggressive fish are dangerous for clownfish. They should not be kept with large Angelfish, Lionfish, Triggerfish, large Wrasse species, and Moray Eels. Clownfish of different species can also show aggression.
Multiple Clownfish
Keeping multiple clownfish in the same aquarium requires caution. The safest option is a pair (one female, one male). More than two clownfish of the same species usually leads to fighting. Different species can also be incompatible with each other. In very large aquariums (400+ liters / 100+ gallons), multiple pairs can be kept, but each pair should have its own anemone.
What to Consider When Buying Clownfish
Captive-Bred vs Wild-Caught
If possible, captive-bred clownfish should be preferred. Captive-bred fish adapt better to aquarium conditions, are more resistant to diseases, and don’t harm natural populations. Wild-caught fish can be more stressed and have a higher risk of carrying diseases.
Health Signs
When choosing a healthy clownfish, pay attention to the following points. It should swim actively and be interested in its surroundings. Colors should be bright and vibrant. Fins should be intact and not frayed. There should be no white spots, cottony patches, or wounds on the body. Breathing should be regular; rapid gill movement is a sign of stress. It should be willing to eat.
Quarantine
Newly purchased clownfish should definitely be kept in a quarantine aquarium for 4-6 weeks. This period allows for the identification and treatment of possible diseases. The quarantine aquarium protects the main aquarium from diseases.
Discover the Marine World
Clownfish are the most colorful and adorable members of the coral reef ecosystem. If you want to get up close with the tropical marine world where these fascinating creatures live, Emaar Aquarium and Underwater Zoo offers you an unforgettable experience.
At Emaar Aquarium, you can discover other inhabitants of the tropical seas where clownfish live. You can observe hundreds of different marine and freshwater creatures up close, including sharks, octopus, arowana, and penguins. Visit Emaar Aquarium to discover the wonders of the underwater world with your children.
Frequently Asked Questions
How long do clownfish live?
They live an average of 10-15 years in aquarium environments. Well-cared-for individuals can exceed 20 years.
How big do clownfish get?
It varies by species. Ocellaris and Percula species reach 8-11 cm (3-4.3 inches), Maroon clownfish can grow up to 17 cm (6.7 inches).
Can clownfish live in freshwater?
No, clownfish are marine fish that can only live in saltwater. They cannot survive in freshwater.
Can clownfish live without an anemone?
Yes, they can live healthily without an anemone in an aquarium environment. However, they are less stressed and behave more naturally with an anemone.
What size aquarium do clownfish need?
A minimum of 100 liters (26 gallons) is required. If an anemone will be added, 200 liters (53 gallons) or larger is recommended.
What do clownfish eat?
They are omnivores. They eat marine fish pellets, frozen mysis shrimp, brine shrimp, bloodworms, and seaweed-based foods.
What species of clownfish is Nemo?
Nemo in Finding Nemo is an Ocellaris clownfish (Amphiprion ocellaris).
Why do clownfish change sex?
Clownfish are born male, and the dominant individual in the group transforms into female. This is an evolutionary adaptation that increases the species’ reproductive success.
Are clownfish aggressive?
They are generally peaceful but defend their anemones and territories. Some species like Maroon clownfish can be more aggressive.
Can clownfish be bred at home?
Yes, clownfish can be bred in home aquariums. However, raising the fry requires special equipment and experience.
