Common squid

The length of the body with tentacles is 50 cm, weight - 1.5 kg. The length of the mantle is usually about 20 cm, but can also reach 40 cm, with males being larger than females ^[3] . The body has a slender, streamlined shape and is painted in gray and red colors. It has paired, horizontal, relatively large lateral fins located on both sides of the mantle, which give the body a diamond shape ^[4] .

The species is distributed in the coastal waters of the eastern North Atlantic from the North Sea to West Africa, as well as in the Mediterranean and Adriatic Seas. It is kept at a depth of about 100 m and more ^[5] , but can also be found at a depth of 400 to 500 m ^{[6] [7]} .

The common squid inhabits different sea depths, both sandy and silty soils. It feeds mainly on fish, as well as crayfish, other cephalopods, as well as polychaete worms and bristles . Sometimes cannibalism is also observed ^[3] .

In the north of the range in the North Sea, reproduction begins in early spring after dark. Animals arrive there before the height of summer. The masonry consists of several oblong, sausage-shaped eggs, which are attached to a fixed substrate at a depth of about 30 m. These can be parts of the seabed, for example, rocks, as well as parts of a living creature, such as calcareous shells of other mollusks, dead organic material or the like. At the same time, several animals prefer to lay their eggs in a common place. Larvae are morphologically similar to adult specimens, differing in the ratio of body parts to each other. Their size during the appearance in June is less than 1 cm ^[7] . The period of embryo development until hatching at a temperature of more than 20 ° C is from 20 to 30 days, at a temperature of less than 15 ° C - from about 40 to 50 days ^{[8] [9]} .

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  Caviar

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  Embryo

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  Embryo

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  Juveniles about 6 mm long (laboratory photograph)

Common squid, especially in the European Mediterranean countries, is an integral part of the diet and therefore it is commercialized. Catching large flocks of mollusks in large quantities is relatively easy, therefore, fishing is economically viable ^[4] .