Big blue octopus
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Great blue octopus ( Octopus cyanea ) |
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| Octopus cyanea | ||||||||||||
| Gray , 1849 |
The great blue octopus ( Octopus cyanea , Syn .: Octopus cyanus ) is a large cephalopod from the order of the octopus . He lives in the Pacific and Indian Oceans from Hawaii to the African east coast.
features
The great blue octopus is a large species of octopus with a maximum length of 120 centimeters and a weight of up to 4 kilograms. It has a round to elongated coat , the skin is smooth without papillae and has several large tubercles . Above the eyes, the animals each have a cirrhus, usually with two secondary smaller tubercles. The coat is mottled and drawn like a net, the arms have purple-brown spots. Between the eyes and the base of arms III and IV there is a dark purple eye spot . The arms are sturdy and upset, the fourth arm is slightly longer than the otherwise equally long arms. In males, arm III bears the hectocotylus , the calmus and the ligula are very small with 0.4 to 1.4% of the arm length and the ligula pit has 10 ribs. The side branches of the gills each have 10 filaments.
distribution
The great blue octopus occurs in the Pacific and Indian Oceans from Hawaii to the east coast of Africa. It lives in warm tropical waters including the Red Sea as well as the coastal waters of India and Australia . It lives benthically , i.e. on the sea floor, in shallow water zones and in coral reefs .
Way of life
The great blue octopus is one of the few species of octopus that forage for food during the day. Like other octopuses, it feeds primarily on other invertebrates. After individual observations, the foraging for food begins early in the morning and shows a further peak in activity in the late afternoon. Individual search activities take place in a range of around 80 meters on average and last around 120 minutes, but can also extend to up to six hours. The animals search for different substrates and reach deep into coral caves with their arms, moving in a "stop-and-go" mode and then swimming back to their cave. Above all, the animals use their eyes to scan their surroundings for potential enemies and search the surfaces.
Systematics
The great blue octopus is classified as a separate species within the genus Octopus . The first scientific description comes from John Edward Gray from 1849. Synonyms are Octopus marmoratus Hoyle, 1885 and Octopus horsti Joubin, 1898.
Economical meaning
The great blue octopus is fished in most regions of its range and is one of the economically most important cephalopods in the reef area of these regions. They are usually caught using traps and spear fishing, where the animals are attracted by light sources.
supporting documents
- ↑ a b c d e Clyde FE Roper; Michael J. Sweeney: FAO Species Catalog Vol. 3. Cephalopods of The World. An Annotated and Illustrated Catalog of Species of Interest to Fisheries. FAO Fisheries Synopsis No. 125, Volume 3, Rome 1984. p. 196 Full text ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. .
- ^ A b John W. Forsythe, Roger T. Hanlon: Foraging and associated behavior by Octopus cyanea Gray, 1849 on a coral atoll, French Polynesia. Ecology 209 (1-2), February 3, 1997. S 15-31. doi : 10.1016 / S0022-0981 (96) 00057-3 .
