Halibut are opportunistic feeders, using whatever food is available. Being strong swimmers, halibut are able to eat a large variety of fish including cod, turbot, pollock, crab, and shrimp.
Younger halibut, up to 10 years, are highly migratory and generally migrate in a clockwise direction east and south throughout the Gulf of Alaska. Older halibut tend to be less migratory.
Fertilized eggs hatch in about fifteen days. Free-floating eggs and larvae float up to 6 months and are transported several hundred miles by the currents of the North Pacific. During the flee-floating stage, many changes take place in the young halibut, including migration of the left eye to the right side of the fish. Eventually as the young halibut are carried into shallower waters by prevailing currents, they begin life as bottom dwellers.
Halibut spawn during the winter. The peak of spawning activity takes place starting in December and lasting through February. Most spawning takes place off of the continental shelf in deep waters of 1200 to 1800 feet. Females lay two to three millions eggs annually, depending on the size of the halibut. Males mature at 7-8 years of age and females mature at 8-12 years.
Being a flatfish, halibut have both eyes on the upper dark side. Their upper sides tend to match the coloration of the ocean floor. Their underside however, being as whitish as it is, tends to blend in well with the sky when viewed from below. These color adaptations allow halibut to avoid detection by both predator and prey.
Halibut is a highly sought after fish. It has very good flavor and the delicate, flaky white meat demands a high price in fish markets. Many people say its the best tasting fish available, hence the nickname "the chicken of the sea".
Halibut live a long time. Females grow faster and live longer than males. The oldest recorded female was 42 years old and the oldest male was 27 years old.