Atlantic halibut (Hippoglossus hippoglossus) is a marine fish of the flatfish family. It has a spike in front of the anal fin. Lateral line with a bend under the pectoral fin. The scales are cycloidal. Length up to 5 m, weight over 300 kg. Inhabits the North Atlantic, Barents and Okhotsk Seas. Keeps at depths from 200 to 700 meters. Matures at the age of 10-14 years. Spawning off the coast of Norway and Iceland at depths from 300 to 1000 m, extended. Eggs are hatched from the end of December to April, at water temperature of 6-7 ° C. Fecundity is from 1.3 to 3.5 million eggs. Young fish feed on zooplankton, adults are predatory, eating cod, herring and other fish. Valuable commercial fish.

Body length can reach 470 cm, maximum body mass up to 320 kg. The fish has a flat, diamond-shaped body. It is more elongated compared to other flatfish. The eyes are located on the right side. The skin is covered with rounded scales, each large scale is surrounded by a ring of small scales. The pectoral fin on the eye side of the body is larger than the fin on the blind side. The mouth is large. The large and sharp teeth are directed backward. Caudal fin with a small notch. Above the pectoral fins, the lateral line forms an arc. The coloration of the eye side of the body is even dark brown or black without markings, young individuals have light irregularly shaped markings on the body. The blind side of the fish is white.

They inhabit the northern part of the Atlantic and adjacent parts of the Arctic Ocean. In the eastern Atlantic they are distributed from Novaya Zemlya and Kolguyev Island to the Bay of Biscay, and in the western Atlantic from the Gulf of St. Lawrence to New York. They are found off the coast of Iceland, the east coast of Greenland, the British and Faroe Islands. In Russian waters they inhabit the southwestern part of the Barents Sea.

They are found at depths of 50-2000 m. Juveniles stay at relatively shallow depths, while adults prefer deeper water. The water temperature in the habitat of these fish varies between 3-8°C. They make long migrations of up to 900 kilometers. Large individuals spend the winter near the Lofoten Islands, and in summer they swim north to Medvezhiego Island and east to the White Sea. It spawns in the Faroe Islands, in the waters near the underwater ridge that runs between Greenland, Iceland and Scotland, in the Denmark Strait, Davis Strait and on banks near Newfoundland.

They reproduce by spawning. Life expectancy according to different sources is from 30 to 50 years. Males reach sexual maturity at 7-8 years, and females at 10-11 years. Halibut spawn at depths of 300-700 meters at temperatures of 5-7°C from December to April-May. Spawning takes place in deep holes along the coast or in fjords. Eggs remain in the sea water column until the larvae emerge. Females hatch 1.3-3.5 million eggs with a diameter of 3.5-4.3 millimeters. According to other data, the eggs are 3.0-3.8 millimeters in size. The larvae hatch in two to three weeks, initially holding in the water column, then settling to the bottom at a length of about 4 centimeters.

Atlantic halibut are a valuable commercial groundfish species. The usual content of omega-3 fatty acids in their meat is 1 gram per 100 grams of fillet, and it is also rich in vitamin D. Nutrient content: fat 4.8 %, protein 18.7, energy value 118 kcal.