Amphiprion clarkii ranges more widely than almost any other anemonefish, occurring from the Persian Gulf and Red Sea across the Indian Ocean, through Southeast Asia, north to Japan, and south to northern Australia and Melanesia. It inhabits coastal reefs and lagoons from roughly 3 to 200 feet. The body is rounder and heavier than that of most clownfish, and base color varies dramatically by collection locality, running from deep yellow and orange through brown to nearly black. Two or three bold white vertical bands cross the body, and the bright yellow tail is a reliable identifying feature. Adults reach about 5 inches, with females noticeably larger than males; like all clownfish, Clarkii are protandrous hermaphrodites. This species is the only clownfish documented to host in all ten known anemone-hosting species, giving it the broadest anemone partnership range in the group.

A 30-gallon aquarium is a realistic minimum for a bonded pair, and a long-format footprint suits their horizontal swimming habit better than a tall tank. Plan on 50 gallons or more if an anemone will be included or if a community of tangs, blennies, or gobies is the goal. Furnish the display with abundant live rock arranged into caves, which serve as shelter and as anchor points for territorial claims, over fine sand or a mixed substrate that echoes their natural sandy-bottom habitat. Clarkii produce more waste than the smaller clownfish species, so strong biological filtration and a protein skimmer rated for at least 1.5 times display volume are worthwhile. Moderate, indirect flow is ideal, since strong direct current tends to pin them into corners.

Introduce Clarkii only to a fully cycled system, with ammonia and nitrite reading zero for at least two weeks. Ammonia exposure in a partially cycled tank is a common trigger for Brooklynella outbreaks in newly added clownfish. A host anemone such as a Bubble Tip is not required, but it is readily accepted and clearly appreciated when lighting and flow can support it.