Parrotfish

Natural history

Parrotfish can be variations of red, green, blue, yellow, gray, brown, or black. Males and females of the same species generally look quite different, and, like wrasses (the Labridae family), a female parrotfish may change into a male. Like moray eels, parrotfish have a second set of teeth—the pharyngeal teeth—located in the back of their throat.

These herbivorous reef fish graze on corals and algae growing on the surfaces of rocks throughout the reef. The strong, beak-like, fused teeth are used to bite off pieces of stony corals. It is not the hard coral skeleton that provides nourishment, but rather the coral polyps that grow on the surface of this skeleton. Living within these coral polyps are symbiotic algae called zooxanthellae.

Conservation

The parrotfish plays an important role in the growth of the coral reef—it feeds on algae that would otherwise smother the coral.

Healthy parrotfish depend on healthy coral reefs. Unfortunately, global warming, pollution, overfishing, and coastal development endanger coral reefs and the animals that live there. A recent census called Reef Check—conducted by scientists and about 5,000 volunteer scuba divers and local fishermen—included a five-year survey of about 300 of the world's coral reefs. The results showed that the number of coral reef animals has seriously declined. For example, spiny lobsters and bumphead parrotfish have disappeared from the reefs they normally inhabit. The Nassau grouper has virtually disappeared, in part due to overfishing, and sea cucumbers are missing from half of the surveyed reefs. But there's good news, too: populations of key species are increasing in marine sanctuaries where fishing is limited.

Cool facts

• A parrotfish swims by rowing itself along with its pectoral (side) fins. Wrasses share this swimming style. The next time you visit our Kelp Forest exhibit, watch how the sheepheads and señoritas swim—they're both members of the wrasse family.
• Parrotfishes produce tons of coral reef sand each year—as much as one ton of sand per acre of reef. The sand-making process begins as a fish grazes on the algal film that grows on coral rock. To feed on the algae, the fish munches on pieces of coral. Molarlike teeth in its throat grind the coral, which then travels through its digestive system and is deposited in the reef as white coral sand.
• Individual species of parrotfish are difficult to identify since they show different color patterns according to age and sex. Early scientists named over 350 species based on the many color forms—now the number of species has been narrowed to about 80.
• The parrotfish is a daytime creature. At night, it burrows in the sand or hides in crevices. Some species even secrete a clear mucous cocoon around themselves at night, which probably masks their scent and helps protect them from predators like sharks and moray eels.
• Their meat is rarely consumed in the United States, but is a delicacy in many other parts of the world. In Polynesia, it is served raw and was once considered "royal food," only to be eaten by the king.