AskDefine | Define tentacle

Dictionary Definition

tentacle

Noun

1 something that acts like a tentacle in its ability to grasp; "caught in the tentacles of organized crime"
2 any of various elongated tactile or prehensile flexible organs that occur on the head or near the mouth in many animals used for feeling or grasping or locomotion

User Contributed Dictionary

English

Etymology

From French tenir and Latin tendere.

Pronunciation

Noun

  1. An elongated, boneless, flexible organ or limb of some animals, such as the octopus and squid.

Translations

elongated, boneless, flexible appendage

Extensive Definition

Tentacles can refer to the elongated flexible organs that are present in some animals, especially invertebrates, and sometimes to the hairs of the leaves of some insectivorous plants. Usually, they are used for feeding, feeling and grasping. Anatomically, they work like other muscular hydrostats.

Tentacles in marine animals

The phylum mollusca includes many species with muscular hydrostats in the form of tentacles and arms (octopuses do not have tentacles: they have arms). Tentacles are longer than arms and usually have suckers at their tips only. Squid and cuttlefish have eight arms like octopuses, and also two tentacles, which is one good way to distinguish squid from octopuses.
The tentacles of the Giant Squid and Colossal Squid are particularly formidable, having powerful suckers and deadly teeth at the ends of the tentacle. The teeth of the Giant Squid are small, "bottle-cap" shaped circular saws, while the tentacles of the Colossal Squid wield two long rows of thick, sharp, finger-length screws of protruding bone.
Cnidarians, which include among others the jellyfishes, are another phylum with many tentaculated specimens. Cnidarians often have huge numbers of cnidocytes on their tentacles. Cnidocytes are cells containing a coiled thread-like structure called nematocyst, which can be fired at potential prey.
Many species of the jellyfishlike ctenophores have two tentacles, while some have none. Their tentacles have adhesive structures called colloblasts or lasso cells. These cells burst open when prey comes in contact with the tentacle; sticky threads released from each of the colloblasts will then capture the food.
Bryozoa (Moss animals) are tiny creatures with a ring of tentacles surrounding the mouth.

Tentacles in amphibians

Some wormlike amphibians have tentacles. The caecilians have two tentacles at their heads, which are probably used for the olfactory sense.

Tentacles in mammals

The star-nosed mole, Condylura cristata, possesses nasal tentacles which are mobile and extremely sensitive, helping the animal to find its way about the burrow and detect prey.

Tentacles in plants

In carnivorous plants, tentacles refer to the stalked glands of the upper surface of the leaves. On a sundew plant, they are hairlike projections with a drop of nectar-like glue which attract insects. When an insect is captured, the tentacles bend inward and the leaf rolls together as shown in the picture. The tentacles then secrete digestive enzymes to dissolve and engulf the insect.

Tentacles in cultural context

The great differences between humans and the tentacle-bearing mollusca have led to tentacles being associated with inhumanity and disgust in legend and fiction. For examples, see:
tentacle in Czech: Chapadlo
tentacle in Danish: Fangarm
tentacle in German: Tentakel
tentacle in Spanish: Tentáculo
tentacle in Esperanto: Tentaklo
tentacle in French: Tentacule
tentacle in Korean: 촉수
tentacle in Indonesian: Tentakel
tentacle in Italian: Tentacolo
tentacle in Lithuanian: Čiuptuvai
tentacle in Dutch: Tentakel
tentacle in Japanese: 触手
tentacle in Norwegian: Tentakel
tentacle in Norwegian Nynorsk: Tentakel
tentacle in Portuguese: Tentáculo
tentacle in Simple English: Tentacle
tentacle in Finnish: Lonkero
tentacle in Chinese: 觸手
Privacy Policy, About Us, Terms and Conditions, Contact Us
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2
Material from Wikipedia, Wiktionary, Dict
Valid HTML 4.01 Strict, Valid CSS Level 2.1