Bicolor Parrotfish

The Bicolor Parrotfish is a large, impressive member of the parrotfish family that undergoes dramatic color changes throughout its life. Juveniles are predominantly white with a broad dark brown to black saddle across the upper body and an orange-red blotch near the head, creating the striking two-tone pattern that gives this species its common name. Initial phase (female) adults develop a mottled pattern of brown, red, and white, while terminal phase (supermale) individuals transform into a spectacular teal-green with pink and purple accents. At a potential maximum size of 36 inches, this is one of the larger parrotfish species encountered in the aquarium trade.

In the wild, Cetoscarus bicolor is found throughout the Indo-Pacific, from the Red Sea and East Africa across the Indian Ocean to the Western Pacific. It inhabits coral reefs and lagoons at depths of 1 to 30 meters, where it performs the ecologically critical function of bioeroding coral rock with its powerful fused beak-like teeth. Parrotfish scrape and bite coral surfaces to access the symbiotic algae and microorganisms within, grinding the coral skeleton into fine sand in the process. A single large parrotfish can produce hundreds of pounds of sand per year, playing a fundamental role in creating the white sand beaches of tropical islands.

In the aquarium, the Bicolor Parrotfish is a challenging species primarily due to its enormous adult size, specialized diet, and constant need for hard substrate to grind with its beak teeth, which grow continuously. A minimum tank of 300 gallons is required, and even this is marginal for a full-grown adult. The fish needs live rock or dead coral skeleton to gnaw on, and its feeding behavior produces significant amounts of fine sediment. It is not reef-safe as it will actively consume coral. This species is best suited for very large fish-only systems or public aquariums.