Steephead Parrotfish / Låggua
Document Actions
Steephead Parrotfish / Låggua
Chlorurus microrhinos
Parrotfishes are closely related to the wrasses (called a'aga in Chamoru), but have teeth that are fused into a distinctive beak. They use their beak to scrape green filamentous algae from the surfaces of dead coral or rock. They also eat large amounts of the dead coral rock that are scraped loose by their beaks. The scraped particles are passed through and settle on the bottom as sand. Some parrotfishes also eat leafy seaweeds or coral. Most parrotfishes travel and feed in groups, sometimes mixed with other algae-eating fishes such as surgeonfishes and rabbitfishes. All parrotfishes sleep on the bottom at night, often tucked away into a hole.
Juvenile parrotfishes are drably colored, usually brown to gray and often striped when less than about two inches long. Larger juveniles, females, and some males of most kinds are brown or gray (these are called palakse'). This is known as the initial phase because both male and female parrotfishes have this color phase after they lose their juvenile color. Some of the largest females eventually change both color and sex to a brilliant and mostly blue and green color phase (these are called låggua). This is called the terminal phase. All terminal phase fish are males that started out as females. Males that started out as males cannot change to the terminal phase color pattern and cannot change sex. The steephead parrotfish reaches a size of about 28 inches (70 cm). Late initial phase individuals of this species become blue green like the terminal phase, but do not have as steep a forehead. These are still called palakse'. When they develop a vertical forehead, they are called "lågguan asut". Parrotfishes are important food fishes. They are caught by nets and spears, but usually will not take a hook. There are 19 different kinds of parrotfishes on Guam.
Guam Comprehensive Wildlife Conservation Strategy, 9/27/2005
