The one thing I've always known about the uhu is that it is a delicious fish. My mom made a wonderful soup with it. We also ate it raw, chopped up and marinated with chili peppers, salt, and seaweed, a concoction known as poki to the locals.
But what's fascinating are the things I learned about it just today after doing some casual research.
The uhu I remember seeing in my youth were approximately 10 to 12 inches in length. But a lot of these reef fish can grow to three feet in length. Amazingly, there is a South Pacific species of parrotfish that measure up to six feet.
The uhu in the photo is most likely an adolescent. As it matures, it metamorphosizes into a beautiful aquamarine-hued fish. Adorned in magnificent greens and blues, the uhu is easily one of the more striking inhabitants of the coral reef.
While primarily a herbivore, the uhu's parrot-like fused teeth are used like a rasp to scrape and ingest morsels of living coral. A collection of plates in its throat--pharyngeal teeth--grind the coral into microscopic pieces, later eliminated as a fine powder by the uhu. True to the natural order of balance in an ecosystem, the uhu is thus an important reef eroder as well as a significant producer of sand. In fact, it is estimated that a large uhu can, in its lifetime, create a ton of sand.
My father, brothers, and I employed a form of fishing known as torching. Equipped with a Coleman lantern seated on a wooden platform which we wore on our chests, and armed with trident spears, we would walk the reefs at night and spear several species of fish from above.
The uhu is a diurnal (active during the daytime) creature and sleeps at night. It secretes a mucousy substance that envelops it like a coccoon. Some scientists believe that this chemical masks its scent and thus protects it from night predators. Other researchers posit that this mucous serves as an anti-parasitic agent, thus protecting the uhu in a different kind of way.
As brilliantly colored as this fish is, the mucous could not protect it from us diligent reef fishermen.