Ocellaris Clownfish: Fish Species Profile

Characteristics, Origin, and Helpful Information for Hobbyists

Ocellaris clownfish on anemone

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Made famous by the movie Finding Nemo, the ocellaris clownfish is a very popular saltwater aquarium fish. They are good for beginners, being hardy fish and a good fit for smaller aquariums, while providing a vivid orange splash of color. They are "reef-safe," leaving corals alone. Through captive breeding programs, many color variations of these fish are readily available. Although not necessary to their survival, the clownfish always appreciates a nice anemone to call home.

Species Overview

Common Names: Clownfish, Ocellaris Clownfish, Common Clownfish, False Percula Clownfish, Clown Anemonefish

Scientific Name: Amphiprion ocellaris

Adult Size: 3 inches

Life Expectancy: 10 to 15 years


Family  Pomacentridae 
Origin  Indo-Pacific, Northern Australia 
Social  Peaceful 
Tank Level  Mid and top-level 
Minimum Tank Size  20 gallons 
Diet  Omnivore 
Breeding  Egg layer,  protandrous hermaphrodite
Care  Easy 
pH  8.1 to 8.4 
Hardness  8 to 12 dGH 
Temperature  77 to 80F (25 to 26C) 

Origin and Distribution

The clownfish has origins in the Eastern Indian Ocean and Western Pacific Ocean. However, most of the clownfish in the pet trade today are captive-bred. When purchasing a new fish, always inquire about where the fish originated from and buy captive-bred animals when possible.

Colors and Markings

The traditional clownfish colors are an orange body with black and white-tipped fins and three white bands edged with black along the back of their head, midbody, and tail peduncle. Starting with the traditional orange with white and black bands, additional varieties with black or white bodies and various white patterns are now common in the pet trade. The orange color can vary from a very light orange to a dark brownish-orange to a deep orange-red, depending on their genetic profile.

The ocellaris clownfish is frequently mistaken for the percula clownfish, giving it the pseudonym "False Percula." The ocellaris species can be differentiated by dark coloring around its eyes and thinner black lines along the large white body bands. They also have 11 dorsal spines, whereas the percula only has 10, but good luck getting them to sit still long enough while you count.


Clownfish are very peaceful saltwater fish and get along with a wide variety of fish and invertebrates. They are coral safe and appreciate a nice soft anemone to play in. Did you know that their skin mucus protects them from the anemone's stings and they help keep the anemone healthy in return by picking off pests? Here are some great ideas for tankmates for clownfish:

Yellow Tang

Yellow tang tankmate for clownfish
Yellow Tang

huynhphuocnhan/Getty Images

Pacific Blue Tang

Blue pacific tang clownfish tankmate
Blue Tang

Charlotte Bleihenberg/Getty Images

Blue Green Chromis

Blue green chromis clownfish tankmate
Blue Green Chromis

aaltug/Getty Images

Clownfish Habitat and Care

Many saltwater aquariums are appropriate for clownfish. Since clownfish only grow to about 3-3.5 inches (7.6–9 cm), they can be kept in smaller aquariums than most other marine fish. Clownfish are even one of the few fish species that will do okay in nano aquarium setups, provided you do not have many other fish in it. Clownfish are also reef safe, so they will not nibble on hard corals and typically leave larger invertebrates alone.

Clownfish are relatively easy saltwater fish to take care of and are hardy enough for most saltwater beginners. This species of saltwater fish stays relatively small and likes to swim in a school, but keep in mind that your tank size must be large enough for all the species you add, and the filtration should be able to keep up with all your fish and invertebrate waste.

With their symbiotic relationship with anemones, you are welcome to add a few to your tank. They are NOT required to keep your clownfish healthy and happy but can certainly improve their welfare and interest. Bubble tip anemones are a good choice for those just getting starting with invertebrates. Be sure to do your research thoroughly before adding just any invertebrate to your tank. Some fish and invertebrate species, including other corals, can be aggressive towards more docile anemones.

Clownfish Diet and Feeding

Clownfish are omnivorous fish, meaning they eat a mix of meat and veggies. Like most aquarium fish, you will see them nibbling at their substrate and anemone home throughout the day. Being warm water fishes, their metabolism is constantly churning, so feeding smaller meals throughout the day is best for their digestion. Clownfish can be intimidated by larger, more aggressive fish, especially during feeding time, so try to scatter the food throughout the aquarium so everyone gets a fair share. However, don't leave uneaten food in the aquarium for long.

Easily bred in captivity, clownfish are usually adapted to a nutritionally complete pelleted diet. You are welcome to add in meaty treats, such as brine shrimp or mysis shrimp, in addition to algae treats and some raw veggies. When it comes to keeping saltwater fish healthy, a varied diet is key. Try experimenting with available saltwater diets to see which your fish prefer, keeping in mind that they need a mix of meats and vegetables.

Gender Differences

Clownfish are all born male. When kept in a group, the largest of the males will undergo transformation into a female. This reproductive strategy is termed protandrous hermaphroditism and is also seen in some species of damselfish. Some dealers will sell bonded pairs of a male and female, with the female always being the larger of the two. When you first establish a population of clownfish, it may take time to have one become distinctively larger than the others. Once this occurs, the largest will become a female with all the others remaining males.

Breeding the Clownfish

Clownfish are one of the easiest fish to breed in captivity. Once you have an established breeding pair, you can encourage them to breed by providing them with a diet with increased levels of protein and fat to encourage gamete production. Move them away from other fish to a designated breeding tank with pristine water quality, and maybe an anemone or two. You may need to try various substrates and décor items in your tank to encourage your fish to breed.

Being external fertilizers, you will see your larger, female clownfish lay a clutch of hundreds of tiny eggs. The male will swim behind her and fertilize them. Once you see the eggs in your tank, your clownfish may tend to the eggs for a little over a week. After the eggs hatch, remove the adult brood stock and start feeding your new fry appropriately. You will need to provide your tiny fish with lots of extra protein and fat to encourage proper development. There are commercial fry foods available, which are fine powders, or feed newly hatched brine shrimp and other small organisms to the baby clownfish.

More Pet Fish Species and Further Research

If you like clownfish, check out these other great saltwater fish species: