Parrotfish

Parrotfish are named for their dentition, which is distinct from other fish, including other labrids; their numerous teeth are arranged in a tightly packed mosaic on the external surface of their jaw bones, forming a parrot-like beak with which they rasp algae from coral and other rocky substrates (which contributes to the process of bioerosion).

Maximum sizes vary within the group, with the majority of species reaching 30–50 cm (12–20 in) in length. However, a few species reach lengths in excess of 1 m (3 ft 3 in), with the green humphead parrotfish can reach up to 1.3 m (4 ft 3 in) TL (though is commonly 0.7 m (2 ft 4 in) SL). The smallest species is the bluelip parrotfish (Cryptotomus roseus), which has a maximum size of 13 cm (5.1 in).

Parrotfish have 10 dorsal soft rays, 9 dorsal spines, 9 anal soft rays, and 3 anal spines.

Most tropical species form large schools when feeding and these are often grouped by size. Harems are typical of most species, with the males vigorously defending their group of females and position from any challenge. As pelagic spawners, parrotfish release many tiny, buoyant eggs into the water, which become part of the plankton. The eggs float freely, settling into the coral until hatching.

A commercial fishery exists for some of the larger species, particularly in the Indo-Pacific, but also for a few others like the Mediterranean parrotfish. Most parrotfish species are not heavily fished, and thus their population dynamics are more likely determined by habitat and recruitment. However, large bodied and long-lived parrotfish species are highly vulnerable to over-exploitation by fisheries.

Despite their striking colors, their feeding behavior renders them highly unsuitable for most marine aquaria.