parrotfishes

Parrotfishes are a diverse group of tropical reef fishes known for their beak-like mouths formed by fused teeth. They are traditionally placed in the family Scaridae, though many taxonomic treatments include them in Labridae. They occur on coral reefs and rocky coasts in the Indo-Pacific and Atlantic Oceans, from shallow lagoons to outer reefs.

Anatomy and feeding: Parrotfishes have strong jaws and fused dental plates that enable them to bite off and crush algae growing on coral, rock, and dead coral surfaces. This feeding behavior makes them among the most important herbivores on reefs. Many species also ingest small amounts of coral polyps and limestone as they graze, contributing to reef bioerosion and reef sediment production; their feeding can create bare patches and sand. At night, some species secrete a mucous cocoon to mask scent from predators.

Life history: Parrotfishes are generally protogynous hermaphrodites, with larger individuals changing from female to male and forming harems around a dominant reproducing male. They spawn in groups or pairs during annual cycles, releasing pelagic eggs and larvae that drift with currents. Juvenile coloration often differs from adults, providing camouflage in different habitats.

Ecology and status: They play a critical role in controlling algal growth on reefs, facilitating coral recruitment. They are threatened by overfishing, habitat destruction, and climate change; some populations have declined due to fishing pressure. They range in size from about 15 to 60 cm, depending on species.