Generally brightly colored, about 60 species of parrotfishes swim in coral reefs around the world. They have fused teeth that form beaklike plates, giving them a parrotlike appearance. They have large thick scales that, in some species, are strong enough to stop a spear.
Their coloring ranges from reds to greens, blues and yellows, as well as grays, browns and blacks. Males and females of the same species generally look quite different and, like wrasses (the Labridae family), female parrotfishes may change into males.
Parrotfishes play an important role in the growth of the coral reef—they feed on algae that could smother the coral if they didn't eat it.
Healthy parrotfishes depend on healthy coral reefs. Unfortunately, global warming, pollution, overfishing and coastal development endanger coral reefs and the animals that live on them. 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.
Parrotfishes swim by rowing themselves along with their pectoral (side) fins. Wrasses (the Labridae family) share this swimming style. The next time you visit our kelp forest exhibit, watch how the sheepheads and the señoritas swim—they're both members of the wrasse family.
Parrotfishes produce tons of coral reef sand each year. The sand-making process begins as the fishes graze on the algal film that grows on coral rock. To feed on the algae, the fishes munch on pieces of coral. Molarlike teeth in their throats grind the coral, which then travels through their digestive systems 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 their age and sex. Early scientists named more than 300 species based on the many color forms—now the number of species has been narrowed to about 60.
Parrotfishes are daytime creatures. At night they burrow in the sand or hide 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.