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octopus |
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octopus, cephalopod cephalopod (sĕf`ələpŏd') ..... Click the link for more information. mollusk having no shell, eight muscular arms or tentacles, a pouch-shaped body, and two large, highly developed eyes. The prey (crabs, lobsters, and other shellfish) is seized by the sucker-bearing arms and pulled into the web of tissue at the base of the arms, paralyzed and partially digested by a poisonous salivary secretion, and chewed by the horny, beaklike jaws and the radula, or tooth ribbon. Octopuses move by pulling themselves along with their arms or by forcibly expelling water through the funnel or siphon in the manner of their near relative, the squid. Sometimes they construct barricades of large stones; most hide in rocky crevices at the approach of danger or cloud the water by ejecting dark "ink" from the ink sac. They also change color (from pinkish to brown) according to mood and environment, sometimes exhibiting rapid waves of color changes that sweep over the body. The 3-ft (91-cm) American devilfish is found off Florida and in the West Indies; a smaller species that reaches only 2 in. (5 cm) is found N of Cape Cod. The common octopus of the Mediterranean and the Atlantic occasionally reaches 10 ft (3 m) in length; the giant octopus of the Pacific may have a diameter of over 30 ft (9 m). Octopuses reproduce sexually. One of the arms of the male is modified into a sexual organ that deposits spermatophores in the mantle cavity of the female. The eggs are encased in capsules and attached to a rock, where the female guards them. The young hatch directly, without a larval stage. Octopus is eaten in many parts of the world. Octopuses are classified in the phylum Mollusca Mollusca (məlŭs`kə) ..... Click the link for more information. , class Cephalopoda, order Octopoda, family Octopodidae, genus Octopus. octopusIn general, any eight-armed cephalopod of the order Octopoda; specifically, members of a large, widely distributed group (genus Octopus) of shallow-water species. Species range from about 2 in. (5 cm) to 18 ft (5.5 m) long with an arm span up to 30 ft (9 m). The head is usually only slightly demarcated from the saccular body. Each arm is contractile and bears fleshy suckers. Two sharp beaks and a filelike organ in the mouth drill crustacean shells and rasp away flesh. Most octopuses crawl along the bottom; when alarmed, they may jet-propel themselves backward, and they sometimes eject an inky substance to cloud the water and protect themselves from predators. They can change colour rapidly, a reflection of their environment or mood. The common octopus (O. vulgaris) is thought to be the most intelligent of all invertebrates. octopus 1. any cephalopod mollusc of the genera Octopus, Eledone, etc., having a soft oval body with eight long suckered tentacles and occurring at the sea bottom: order Octopoda (octopods) 2. another name for spider octopus [′äk·tə‚pu̇s] (invertebrate zoology) Any member of the genusOctopusin the family Octopodidae; the body is round with a large head and eight partially webbed arms, each bearing two rows of suckers, and there is no shell. How to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit webmaster's page for free fun content. |
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