All clownfish are born males and become females later if necessary.
Some information from Wiki:
Clownfish, or amphiprions (Latin Amphiprion) are a genus of marine fish from the pomacentral family. Most often, this name refers to the orange amphiprion fish (Amphiprion percula).
Clownfish are symbiotic with various species of anemones. At first, the fish lightly touches the anemone, allowing it to sting itself and figuring out the exact composition of the mucus that the anemones are covered with - the anemone needs this mucus so that it does not sting itself. Then the clownfish reproduces this composition and after that it can hide from enemies among the tentacles of the sea anemone. The clownfish takes care of the anemones - it ventilates the water and carries away undigested food debris. Fish never move far from their "own" anemones. Males drive males away from her, females - females. Territorial behavior seems to have caused the contrasting coloration. Protandric hermaphrodites: all juveniles are males, but during life the fish changes sex. The stimulus that triggers the sex change is the death of the female.
The color of fish ranges from deep purple to fiery orange, red and yellow.
28 species inhabit the reefs of the Indian and Pacific Oceans - from East Africa to French Polynesia and from Japan to Eastern Australia.