Clown fishes live in close association with large sea anemones. Each species has a preferred anemone host, although, most occasionally occur in a number of other anemone species, and individual anemones occasionally host more than one species of anemone fish.
They never live without an anemone, but it is not uncommon to find suitable anemones without anemone fish. Large anemones often host a semi permanent monogamous pair of adult anemone fishes and several small juveniles. Anemone fish are protandrous hermaphrodites, that is all individuals mature as males, and all females are sex-reversed males. Sex and growth are socially controlled by a dominant female. In the absence of a female, the largest male will turn into a female and the largest juvenile will rapidly mature into a male. The growth of the remaining juveniles is stunted by the adult pair. Spawning usually takes place around the full moon, all year round in the tropics, but only during the warmer month in warm-tempered areas. Typically, several hundred adhesive eggs are laid in a patch of cleared rock near the base of the anemone and cared for by the male. Hatching occurs at night after about a week, and the larvae drift in the plankton for 16 days or more before settling and seeking an anemone host. Anemone fishes feed primarily on zooplankton.