Hawaiian Reef Fish and Parrotfish

Parrotfish are among the largest and most beautifully colored reef fish among Hawaiian coral reefs. Of the seven known species of parrotfish native to Hawaiian waters, three are endemic to the Hawaiian Islands – Spectacled Parrotfish, Regal Parrotfish, and Yellowbar Parrotfish. They grow in size from 12 inches to nearly 3 feet, with a single continuous dorsal fin, and swim with lazy rowing motions of their pectoral (side) fins. The tail is also used for propulsion, especially when a burst of speed is required.

Initial phase adult Parrotfish may be male or female, and are colored drab gray or reddish-brown. Terminal phase parrotfish are females that have become males (also called dominant males, or super males), and these are the largest and most colorful of the parrotfish – often bright green or blue-green. Hawaiian names for the growth stages of the Parrotfish include ‘ohua for very young fish, panuhu for medium sized fish, and uhu refers to mature Parrotfish.

Parrotfish are herbivorous, and feed by scraping algae off the surface of coral reefs. They bite into the live coral using their fused teeth, and ingest the coral along with the algae. They have grinding plates in the back of the throat that help the fish break down the bits of coral into fine sand. With no true stomach, but with an exceptionally long intestine, they grind the coral into sand, and then expel the sand. A single adult parrotfish may produce up to 1 ton of sand per year, making it a major contributor to the sand supply around the Hawaiian Islands.