Halibut is a flatfish from the family of the right-eye flounders. The Atlantic halibut is the largest of the flatfish and one of the largest marine fish in the UK. Adults are generally bottom dwelling and feed mainly on other fishes (cod, haddock, pogge, sand-eels, herring, capelin), but also takes cephalopods, large crustaceans and other bottom-living animals. 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.
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. Halibut are batch spawners, reaching sexual maturity at approximately 10 to 11 years of age, or at a length of 70 to 100 cm. Halibut feed on almost any animal they can fit into their mouths. Animals found in their stomachs include sand lance, octopus, crab, salmon, hermit crabs, lamprey, sculpin, cod, pollock, herring, and flounder, as well as other halibut. Halibut live at depths ranging from a few meters to hundreds. Although they spend most of their time near the bottom they may move up in the water column to feed.