Most of our parrot-fish species here in Hawai‘i are called “uhu,” but one species has a totally different Hawaiian name. Uhu feed mostly on coral, biting off chunks then digesting the soft coral polyps while pooping out the crushed coral structure.
The name “uhu” means “to have loose bowels” in Hawaiian, and that is because the fish are constantly pooping out the ground coral. Ponuhunuhu is different because it feeds on leafy algae that grows on the reef, and it bites the algae off of the reef with its strong beak, which is made up of many teeth that are fused together.
The 20-inch long male star-eye parrot-fish is bright blue or green and has a pink, star-like pattern around the eye. The females look totally different, as they are just a solid gray color. All of the ponuhunuhu are hatched out as females, and one adult female will turn into a male for the purpose of breeding.
The fish will turn from gray to blue, and the large, colorful male is called a “super male.” These males are quite territorial, and a single male may mate with eight to 10 females, producing millions of eggs.
This is why it is so important to never take a mature super male off of the reef, because if it dies there will be no reproduction until one of the remaining females converts into a breeder male, and that process may take well over a year.
Ponuhunuhu lives in shallow water, where there is more algae to eat, and that algae needs sunlight to grow. You will often see the stareye parrot-fish feeding right in the middle of a large school of manini or convict tangs. This way the parrotfish can feed and also be hidden from predators in the middle of a large school of fish. During the day ponuhunuhu is usually more of a green color that matches the color of the reef, but at night when it sleeps close to shore in a crack on the reef it turns bright blue!
In the dive lights at night you can spot a male star-eye from 30 feet away because it is so brightly colored. I am not sure why these fish get so colorful when they sleep, but I am sure they have evolved to do this for a good reason.
The star-eye parrot-fish is also unique because it is the only parrot-fish species that will rest on the sea floor or in a cave and not move for hours at a time.
All of the other parrot-fish species are constantly moving during the day but do sleep motionless at night.
You can see ponuhunuhu in the movie “The World’s Guide To Hawaiian Reef Fish” on the marine-life educational web page at www.underwater2web.com.
Terry Lilley is a marine biologist living in Hanalei and co-founder of Reef Guardians Hawai‘i, a nonprofit on a mission to provide education and resources to protect the coral reef. To donate to Reef Guardians Hawai‘i go to www.reefguardianshawaii.org.
Source: The Garden Island