Parrotfish – Scaridae, as researchers usually refer to them by their scientific name – are a sizable group of marine fish that normally inhabit the shallow waters around coral formations and coastal areas. They play a significant role in the food web of most areas, and they also assist – either directly or indirectly – in enriching the biodiversity of certain regions to a great extent. Despite the fact that parrotfish can grow to significant sizes, depending on the species, they are detritivores known to feed on a variety of microscopic organisms that live in the substrate.
Most parrotfish species can be located in coastal areas. From rocky coasts to rich coral reefs and sea grass beds, the fish are quite prevalent in numerous locations throughout the world’s seas and oceans. They are the richest species of fish found in the Indo-Pacific, and they also play a particularly important role in maintaining the health of the Great Barrier Reef ecosystem.
The curious name attributed to parrotfish comes from the unique development of their teeth. Scaridae is the only group of fish that has its teeth arranged in a mosaic-like pattern on the outer edge of their jaw bones. The parrot-like shape they form has become the main sign by which divers and scientists distinguish parrotfish from other labrids. When it comes to most species of parrotfish, Scaridae size differences can be quite substantial. Even though some of the smaller species can only grow up to 30 cm in length (the smallest species being the bluelip parrotfish, with a length of only 13 cm), there are species that can grow to remarkable sizes. A good example is the green humphead parrotfish that can reach up to 1.3 meters in length.
When it comes to their feeding habits, parrotfish are known to eat a significant variety of microscopic organisms, including coral polyps. They feed in large schools, biting at rocks and coral to find invertebrate prey. While feeding, most parrotfish species also grind up coral and coralline algae with their refined, pharyngeal teeth. This action results in the actual formation of sand. In fact, a single green humphead can produce more than 90 kg of sand in a single year, and in some areas parrotfish are considered to be the main producers of sand in the entire reef. In the Caribbean, an important role played by parrotfish, Scaridae experts affirm, is made possible by their affinity to sponges – which would otherwise grow much too fast and prevent reef-building coral from thriving as easily.