Clark's anemonefish or the Yellowtail clownfish (Amphiprion clarkii) is a widely distributed clownfish. It is found in tropical waters, in lagoons and on outer reef slopes, from the Persian Gulf to Western Australia and throughout the Indian Ocean and Pacific Ocean as far as Melanesia and Micronesia, and as far north as Taiwan, southern Japan and the Ryukyu Islands.
Clark's Anemonefish is a spectacularly colourful fish, with vivid black, white and yellow stripes, though the exact pattern shows considerable geographical variation. There are normally two white bands, one behind the eye and one above the anus. The tail fin may be white or yellow, but is always lighter than rest of the body. Amphiprion clarkii was recently observed to coexist with the Orange skunk clownfish Amphiprion sandaracinos within one host anemone of Stichodactyla mertensii.