Length up to 7 ft.
Food.—Crustaceans and molluscs, and fish.
Range.—Round the British Isles and along the coast of Western Europe.
Turbot—not very abundant. It inhabits the deeper parts of the North Sea.
Brill—inhabits southern waters, and is fairly abundant.
(c) The Raüdac.
Skates and rays—found all round Britain, more particularly the Western area of the English channel.
(2) The various species of fish that inhabit the surface waters of the sea are called “pelagic.” They include the herring, mackerel, tunny, flying fish, sword fish, and many sharks, also various marine mammals, such as whales, grampuses, porpoises, dolphins. Amongst pelagic fish are included some of the smallest (plankton) as well as some of the largest (whales) of all living creatures. Pelagic fish pass their whole life swimming at or near the surface. They enter the shallow water offshore only for prey or, in some cases, periodically to spawn. The majority spawn in the open sea, far from land. Unlike demersal fishes, the distribution of the different species of pelagic fishes depends very much upon local conditions of light, water temperature, and the character and quantity of food available. They do not hunt their food individually to the same extent as demersal fishes, but generally filter it from the water as it passes through their gill-openings. Although not so widely dispersed as demersal fish, they are, in favourable circumstances, dispersed over large areas by swimming and by ocean currents.
All pelagic fish are “round.” With the exception of the mackerel, the important edible pelagic fishes belong to the herring family, and are known as the Clupeidae. They include—
Herring—found from the White Sea to the Bay of Biscay. It is the most abundant of all food fishes.