Bright orange with three distinctive white bars, clownfish, also called anemonefish, are among the most recognizable of all reef-dwellers. They reach about 4.3 inches in length, and are named for the multicolored sea anemone in which they make their homes.
There are at least 30 known species of clownfish, most of which live in the shallow waters of the Indian Ocean, the Red Sea, and the western Pacific. They are not found in the Caribbean, Mediterranean, or Atlantic Ocean.
Surprisingly, all clownfish are born male. They have the ability to switch their sex, but will do so only to become the dominant female of a group. The change is irreversible.
Clownfish perform an elaborate dance with an anemone before taking up residence, gently touching its tentacles with different parts of their bodies until they are acclimated to their host. In exchange for safety from predators and food scraps, the clownfish drives off intruders and preens its host, removing parasites.
The orange clownfish, which inhabits Coral Triangle region of the tropical Indo-Pacific, spends nearly its entire life protected within anemones on coral reefs. While it is currently classified as Least Concern, climate change and increasing ocean acidity, both resulting from carbon dioxide pollution, threaten the clownfish’s anemone and coral reef habitat. Warm-water-driven bleaching events reduce anemone size and numbers. Ocean warming degrades and destroys coral reef habitat by increasing the frequency and intensity of mass bleaching events, while ocean acidification slows coral growth.