Orange through brown to nearly black, crossed by two white bars, and never more than a body length from the anemone it lives in. Males reach about 10 cm (4 in) and females 14 cm (5.5 in), and the darkening with age means a big black fish and a small orange one in the same anemone are the same species.
The anemone is home, larder and fortress. The fish is protected from the stinging tentacles by a mucus coat it builds up by touching them carefully over hours until the anemone stops recognizing it as prey; in exchange it drives off butterflyfish that would eat the anemone, and fans water through the tentacles at night, which measurably improves the anemone's oxygen supply. Neither animal does well alone.
Everyone is born male. The largest fish in an anemone becomes the female, the second largest is the breeding male, and the rest wait in line as non-breeders. When the female dies, the male changes sex and the next in line moves up - a system that means a resident group can lose its female without losing its future.
Eggs are laid on cleaned rock at the base of the anemone and guarded by the male, who fans them for a week and eats the ones that fail.
The genus. Amphiprion Bloch & Schneider 1801 - amphi- (around) + prion (saw). ETYFish
- orange to almost black body with two white bars edged in black
- never more than a body length from its anemone
- the largest fish in the anemone is the female, the second largest the male
- length up to 14 cm
