Common octopus

Common octopus (Octopus vulgaris)

Called The common octopus or Common Octopus (Octopus vulgaris), only partially octopus (plural octopuses ), is a large cephalopod from the order of octopus.

Features

The pallium ( the shell -like back surface ) of the ordinary octopus has a wide opening and is up to 25 inches long; the tentacles reach a length of up to one meter and are occupied by two rows of suckers. The dorsal ( back ) arms are the shortest. The lateral ( side ) arms are longer than the anterior ( front ), the ventrolateral arms are somewhat longer than the dorsolateral arms. The siphon is W-shaped. An ink bag is available. The common octopus has no ocelli ( simple eyes ) between the eyes and the base of the lateral arms. The common octopus has no shell. This enables the computer to excessive mobility and makes it possible for him to squeeze through the smallest openings.

Distribution area

The common octopus occurs worldwide in the seas of tropical and temperate zone, most commonly near the UK and the Southeast Asian coast. The real common octopus may be circulated only in European and North African waters.

The species colonized the benthos of the coast to the outer edge of the continental shelves at depths up to 200 meters, where the common octopus encounters a variety of habitats such as rocks, coral reefs and seagrass beds.

System

Evidence of Octopus vulgaris are from the world's oceans, with the taxonomists are agreed that it is a species complex. The relationships between the various populations have not yet been investigated.

Nutrition and reproduction

The common octopus feeds mainly on crustaceans ( crab and lobster -like ) and molluscs (mussels and snails).

Females produce 120000-400000 eggs, which are stored in strings, especially in crevices and caves of shallow waters. Spawning can last up to a month. During the breeding season ( 25-65 days, depending on water temperature), the females take almost no food, so many die after hatching the larvae para. The developing octopus (Para larva ) is planktonic.

The common octopus living in the wild up to two years, but can be up to three years in captivity under optimal management conditions.

Fishing

The common octopus is mainly caught for human consumption and as freshly caught goods, frozen or bought dried and salted. According to the Food and Agriculture Organization 1999 34.262 tonnes were caught, with Mexico with 19 081 and Italy with 8,844 tons caught the largest quantities.

General decline of catches since the late 1960s. At that time, more than 100,000 tons were caught per year.

Evidence

• Michael Hutchins ( Ed.): Grzimek 's Animal Life Encyclopedia, 2nd edition. Volume 2, protostomes, Farmington Hills, MI: Gale Group, 2003.