The Parrotfish gets its name from its parrot-like mouth. Parrotfish is actually the common name for 80 different species of fish in the Scaridae family, commonly found on tropical coral reefs. Interestingly, this fish can change sex, many are born female but gradually become male. They live and forage around coral reefs, so they often have very large scales to protect them against the sharp edges of coral. At night, Parrotfish secrete a slimy substance from their mouths around their bodies to hide from predators.

These fish can also change colour throughout their life cycle. So even males, females and juveniles of the same species can have different colours. The representative species of parrotfish in the Indo-Pacific region is the Callyodon fasciatus. They grow to 46cm or more in length. The males are green and orange or red, the females are blue and yellow.

The representative species of parrotfish in the Atlantic include the Rainbow Parrotfish and the Queen Parrotfish. The Rainbow Parrotfish grows to 90cm in length, is bright orange and green with a blue bill. Meanwhile, the Queen Parrotfish (Scarus vetula) grows to about 50cm in length. The males are blue with green, red and orange. The females are red or purple and have white stripes.

The secret lies in the teeth

According to Dr. Ayana Elizabeth Johnson, Executive Director of the Waitt Research Institute (a non-profit organization that restores coral reefs and fisheries based in Washington, USA), parrotfish eat seaweed, seaweed and especially their "favorite food" is dead coral.

The fish has large scales and a beak-like mouth. It is thanks to its hard jaws and extremely strong teeth that it can scrape algae and chew coral. In fact, its teeth are so strong that Professor Pupa Gilbert, a biophysicist at the University of Wisconsin-Madison, has proposed using the tooth structure of this fish to study materials for making new-generation artificial machines.

The special teeth of the parrotfish are capable of crushing coral, then their digestive system will work and excrete fine sand. It can be said that they are the "hardest, most diligent workers" in the process of cleaning coral reefs. This is important because most coral reefs across the tropics are being obscured by algae because there are not enough parrotfish and other herbivorous fish.

Parrotfish need to be protected

After eating dead coral, they excrete fine sand. It may be hard to believe, but each parrotfish can produce up to 320kg of fine sand in a year. 100 parrotfish produce 3.2 tonnes of sand in a year!

Unfortunately, overfishing has caused the number of parrotfish to decline significantly in recent years. There are no longer enough of them to sustainably exploit in the Caribbean Sea as they once did. This is due to overfishing by humans for commercial purposes. In particular, the largest and most easily caught fish are males. This makes it even more difficult for the fish to reproduce.

These colorful fish need to stay in the sea. And when they do, they do great things. A report concluded that coral reefs where parrotfish were abundant in the 1980s are the healthy reefs today.

“The number one thing we can do to ensure the survival of our reefs is to protect the parrotfish,” says Dr. Ayana Elizabeth.

Barbuda is the first to act. The local government has passed a law protecting the parrotfish. It is illegal to catch, buy, sell or possess parrotfish on the island. In addition, 33% of the coastal area is protected in marine reserves and the use of nets on coral reefs is prohibited. Barbuda is a small island, but it has set a new standard for ocean stewardship.