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The Common Clownfish
by Michael L. Pettigrew

General Information
The beautifully bold and unforgettable coloration of the Common Clownfish makes it the one that everyone recognizes. It is most commonly pictured frolicking among the tentacles of an anemone. This commensal, (sometimes called symbiotic), relationship is unique and both draw an advantage from it in nature by protecting each other. Additionally, wastes from the clownfish's feeding helps to feed the anemone.

While this commensal relationship is necessary in the wild, as without it the clownfish would be quickly consumed by larger fish. In the aquarium, both can survive quite successfully without the other. This is very fortunate, since anemones have proven to be very hard to keep alive for any length of time in an aquarium, and clownfish can be quite long lived.

Clownfish are territorial by nature, and should be kept alone or as a mated pair in an aquarium. If you choose to keep an anemone, it should be a natural host to this particular clownfish. If an anemone is not chosen, then it is necessary to provide shelter for clownfish.

The Common Clownfish is the most commonly kept clownfish in the hobby today. It is argued that this fish is really two species - Amphiprion ocellaris and Amphiprion percula. However, it is possible that these two species are one in the same in different locations. The true Perculas, A. Percula, is often differentiated by black borders of varying width along the white bands. While the A. ocellaris has a very thin even, or no black line bordering the white. Many, of these particular clownfish that you see, are captive bred. This makes them even better suited to aquarium life, and less susceptible to diseases.


Fish Health
Clownfish are suitable to the newcomer to the hobby. Captive bred ones can even be considered hardy. They respond well to reasonable care. However, in poor conditions are susceptible to Whitespot, Oodinium, and other parasitic diseases. Copper medications are generally helpful though there is no substitute for good conditions. Good conditions are the key to long-term success. Clownfish have been kept in captivity in excess of eighteen years.


Tank Setup
A tank of 30 gallons or larger is best suited, however due to their smaller size, a single pair of Common Clownfish can be kept in tanks as small as 10 gallons. This though should be left to the more experienced as water quality can change quickly if not closely monitored. If an anemone is also chosen then strong lighting, adequate water movement and excellent water quality will be necessary. If an anemone is not chosen, then it is necessary to provide shelter for them. This can be accomplished by using rocks to construct a small cave or crevice to function as a retreat. They should not be kept with the more aggressive species such as dottybacks or triggers, nor should they be kept with larger fish eating species like morays, groupers and lionfish. These fish are ideal in the invert aquarium.


Feeding
Clownfish are not picky eaters, being omnivorous they accept most offered foods. They should be fed a varied diet of finely chopped seafoods, planktonic foods, frozen preparations and a well-balanced flake food, (preferably one containing algae and vitamin C).


Water Chemistry
Good water quality is always wanted. A pH of 8.1-8.3, temp from 77-82F, specific gravity of 1.020-1.024 and nitrate of <20ppm in a FO system and <5ppm in a Reef or with an anemone.


Breeding
These are some of the easiest marine fish to spawn and raise in captivity. Clownfish possess the ability to change sex. All are born as males. The dominant fish will become the female and be the largest one. A mated pair can be purchased, or you can buy a small (1/2" long) pair and let them grow up together. This will take some time, though is quite rewarding. A 30 gal. tank with no other inhabitants is good for this purpose. Eggs are generally laid on a flat surface, close to or under the protection of the host anemone. Eggs are mainly cared for by the male and hatch in 7-10 days. Once hatched the larvae (not fry in the true sense yet) migrate upwards to the plankton layers to feed and develop.