Chela (arthropod)

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Limbs without, with chela, subchela and carpochela
Subchela and simple pereiopod

As chela (from Latin chela , 'claw'; pl. Chelae ) claws or claws on the limbs of arthropods are called.

Chelae can exist in a variety of forms and serve different functions. So they will u. a. used to hold the sexual partner, grabbing and chopping up food and to ward off enemies or rivals. In the case of the fiddler crabs , they also have an impressive function during courtship .

All Chelae have in common that a movable limb, the dactylus, can be moved against a stiff limb, propodus or carpus. Strictly speaking, one speaks of a chela only if the propodus is thickened proximally and elongated and pointed distally, i.e. can be differentiated in the scissor hand and finger. In a subchela , the dactylus is usually shaped into a hook and the propodus is widened at its distal edge. In a carpochela , in addition to the dactylus and propodus, the carpus is part of the grasping organ.

Limbs that have a pair of scissors, are as chelation or Cheliped referred. If chelate limbs of the head segments are used for food intake, they are also known as gnathopods .

The size, type and shape of the claws was often the eponymous detail of many taxa . For example, the crabs of the Achelata have no claws and those of the Polychelidae have claws on all five pairs of striding legs ; the Chelicerata have so-called chelicere , mouthparts provided with chelae.

literature

  • Alfred Kaestner: Textbook of special zoology . Ed .: Hans-Eckhard Gruner. 4th edition. tape 1 : invertebrates; 4th part: Arthropoda (without Insecta). Gustav Fischer Verlag, Jena Stuttgart New York 1993, ISBN 3-334-60404-7 , p. 470 f., 930 f .

Web links

  • Joel Martin: Chela. In: Crustacea Glossary. Natural History Museum Los Angeles County, accessed July 5, 2012 .
  • Joel Martin: Chelate. In: Crustacea Glossary. Natural History Museum Los Angeles County, accessed July 5, 2012 .
  • Joel Martin: Cheliped. In: Crustacea Glossary. Natural History Museum Los Angeles County, accessed July 5, 2012 .
  • Joel Martin: Subchela. In: Crustacea Glossary. Natural History Museum Los Angeles County, accessed July 5, 2012 .
  • Joel Martin: Carpochelate. In: Crustacea Glossary. Natural History Museum Los Angeles County, accessed July 5, 2012 .