Parrotfishes

Nature

Parrotfishes

Midnight Parrotfish

Known as Gutu in Papiamentu, these distinctively colorful fishes play an important role in protecting our coral reefs. Why? Coral and certain types of algae compete for space on the reef. In recent decades, the amount of reef algae has increased dramatically throughout tropical reefs worldwide – effectively smothering the corals by choking off oxygen and disrupting helpful bacteria. Have you ever heard a crunching noise on the reef while watching a parrotfish? These fishes eat algae and detritus with their beak-like front teeth, making a distinctive sound. Without constant grazing from herbivores like parrotfishes, the algae grows tall and thick, overgrowing coral. By keeping algae in check parrotfish indirectly help maintain the health of coral reefs. That is why on Bonaire, it is illegal to harvest parrotfishes or use the types of traps that might accidentally catch them. Additionally, as parrotfish scrape algae they remove the top layer of rock from the reef. They grind this up and excrete it as sand- adding variety to the habitat on the reef and helping create the beaches we enjoy.

Queen-Parrotfish
Queen Parrotfish: Initial & Terminal Phases

Maintaining healthy reefs is not the only cool thing these iconic fishes do. All but one species of parrotfish are sequential hermaphrodites- meaning that they change sex part way through their life. In the case of parrotfish, they are born female (Initial Phase) and transition to males (Terminal Phase). The transition is triggered by the size of the fish and group social cues. The same species looks drastically different at various stages of their life depending on their age and sex. On a night dive, look for species like the Queen parrotfish (Scarus vetula) sleeping in a mucous cocoon. Scientists believe they create these cocoons as a type of “mosquito net” to protect them from small parasites.

Rainbow parrotfish
Rainbow parrotfish

The largest parrotfish species on Bonaire is the charismatic Rainbow parrotfish (Scarus guacamaia), which can grow over 1m (3.2’) in length! Rainbow parrotfish are listed as Near Threatened by the IUCN Red List and has gone extinct in certain parts of the Caribbean due to overfishing and habitat loss. The good news is these fishes have their highest population density here on Bonaire. Keep your eye out for these big beauties when diving or snorkeling at the northern dive sites that they frequent.