The Black clownfish (Amphiprion clarkii) is also known as Clarkii clownfish and Yellowtail clown fish, and can be obtained in several colour variations. The most common form of Black clownfish is black and yellow with white vertical stripes. Just like the other clownfishes, These fish form a symbiotic relationship with anemones and are therefore also known as Black anemonefishes.

The Black clownfish is one of the most frequently kept clownfish species and you can find these fishes in numerous saltwater aquariums all over the world. It's native region is the warm Indo-West Pacific Ocean. Populations are found from the Persian Gulf to the Western coast of Australia. They inhabit the Indo-Australian archipelago, the many reefs of Melanesia and Micronesia, and you can also find them up to north Taiwan and south Japan.

The vibrant coloration of the fish makes it very easy to spot for predators, and it would not survive long in the wild if it was not protected by the tentacles of the stinging anemone. The Black clownfish will keep the anemone clean by eating left over food. When kept in an aquarium without any natural enemies and is provided with food by the aquarists, it does not need an anemone to survive. You should however make sure that the aquarium set up provides it with suitable hiding spots, since it can be very stressed in a barren aquarium, especially when no anemone can be found.

In the wild, these fish known to co-habit with a wide range of different anemone species. If you keep your fish with an anemone species that it has not encountered before, the Black clownfish must gradually acclimatize itself to the anemone to avoid begin injured. Examples of anemone species that Black clownfish are known to appreciate in the wild are Stichodactyla mertensii, Stichodactyla haddoni, Stichodactyla gigantean, Macrodactyla doreensis, Heteractis malu, Heteractis magnifica, Heteractis crispa, Heteractis aurora, Entacmaea quadricolor and Cryptodendrum adhaesivum.

The Black clownfish can be kept in a comparatively small aquarium since it grows no bigger than 5 inches (13 centimetres) and claims a very small territory. A 20 gallon (75 litres) aquarium will be enough. You should however keep in mind that it requires supreme water quality and keeping the levels of soluble waste down will be much easier in a bigger aquarium. In the wild, the territory of a Black clownfish group is limited to the immediate area around an anemone. It is however known to occasionally leave its host anemone to attack nearby fish. This habit makes it more aggressive than the other clownfish species.

Since the Black clownfish is native to warm, tropical parts of the world it can only be kept in tropical aquariums. The temperature must be in the 75-82 F (24-28 C) range for it to do well. The pH should be around 8.3-8.4.

Your Black clownfish should be provided with a meaty diet in the aquarium, since it is used to feeding on the scraps left by the predatory anemone. Chopped fish and shellfish is usually appreciated. It will also require some vegetables and algae to stay healthy. You can usually get them to accept flake food, but keeping it on nothing but flakes is not recommended.