Halibut is a common name principally applied to the two flatfish in the genus Hippoglossus from the family of right-eye flounders. Less commonly, and in some regions only, other species of flatfish are also referred to as being halibuts. The word is derived from haly (holy) and butte (flat fish), for its popularity on Catholic holy days. Halibut are demersal fish and are highly regarded as a food fish.[
Halibut are often boiled, deep-fried or grilled while fresh. Smoking is more difficult with halibut meat than it is with salmon, due to its ultra-low fat content. Eaten fresh, the meat has a clean taste and requires little seasoning. Halibut is noted for its dense and firm texture.
The Pacific halibut is the world's largest flatfish. The IGFA record was apparently broken off the waters of Norway in July 2013 by a 515-pound 8.6 foot fish. This is awaiting certification as of 2013. In July 2014, 76-year-old Jack McGuire caught a 482-pound Pacific halibut in Glacier Bay, Alaska (this is, however, discounted from records because it was shot to prevent injury to those on the boat).
Halibut are dark brown on the top side with an off-white underbelly and have very small scales invisible to the naked eye embedded in their skin. Halibut are symmetrical at birth with one eye on each side of the head. Then, about six months later, during larval metamorphosis one eye migrates to the other side of the head. The eyes are permanently set once the skull is fully ossified.  At the same time, the stationary-eyed side darkens to match the top side, while the other side remains white. This color scheme disguises halibut from above (blending with the ocean floor) and from below (blending into the light from the sky) and is known as countershading.