The halibut is the largest flat fish, averaging 11–13.5 kilograms but can be as large as 350kg.
They are gray-black on the top side with an off-white underbelly and have very small scales invisible to the naked eye embedded in their skin. At birth they have an eye on each side of the head, and swim like a salmon. After six months one eye migrates to the other side, making them look more like flounder.
At the same time the stationary-eyed side darkens to match the top side, while the other side remains white. This colour 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.
Halibut are often broiled, 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.