Cercus

Cercus
A common earwig with large cerci in the background.

Cerci (singular cercus) are paired appendages on the rear-most segments of many arthropods, including insects and arachnids but not crustaceans. Cerci often serve as sensory organs, but they may also be used as weapons or copulation aids, or they may simply be vestigial structures.

Typical cerci may appear to be jointed and hair-like, but they can take very different forms. Earwigs and some diplurans have large, stout pincer-like cerci. Crickets have particularly long cerci while other insects have cerci that are too small to be noticeable. Some insects such as mayflies have an accompanying third tail filament which extends from the tip of the abdomen. Aphids have tube-like cornicles or siphunculi that are sometimes mistaken for cerci.

Like a surprising number of insect body parts, including mandibles and antennae, cerci are thought to have evolved from what were legs on the primal insect form; a creature not unlike a caterpillar, velvet worm, or centipede, worm-like with many pairs of legs, one for each segment.

References


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Игры ⚽ Поможем написать курсовую

Look at other dictionaries:

  • Cercus — Cer cus, n.; pl. {Cerci}. [NL., fr. Gr. ke rkos tail.] (Zo[ o]l.) See {Cercopod}. [1913 Webster] …   The Collaborative International Dictionary of English

  • Cercus — Cercus, eine Art Glanzkäfer (Nitidula) …   Pierer's Universal-Lexikon

  • CERCUS — Bithyniae collis. Cedrenus …   Hofmann J. Lexicon universale

  • cercus — [sʉr′kəs] n. pl. cerci [sʉr′sī΄] [ModL < Gr kerkos, tail] either of a pair of usually jointed, feelerlike appendages at the hind end of the abdomen of many insects …   English World dictionary

  • Cercus — Als Cercus (von griech. kerkos = „Schwanz“; Plural Cerci, auch Afterraife, Analraife, Afterfühler, Raife) werden die paarigen Hinterleibs Anhänge am letzten Hinterleibssegment bei Tracheentieren, also den Sechsfüßern (Insekten, Springschwänze,… …   Deutsch Wikipedia

  • cercus — noun (plural cerci) Etymology: New Latin, from Greek kerkos Date: 1826 either of a pair of simple or segmented appendages at the posterior end of various arthropods that usually act as sensory organs …   New Collegiate Dictionary

  • cercus — n.; pl. cerci [Gr. kerkos, tail] (ARTHROPODA) One of a pair of appendages that arise at the posterior of the abdomen of arthropods that function as sense organs; abdominal filaments; acrocercus; anal forceps; anal styles; anal stylets; caudal… …   Dictionary of invertebrate zoology

  • cercus — cercal, adj. /serr keuhs, ker /, n., pl. cerci /serr suy, ker kee/. one of a pair of appendages at the rear of the abdomen of certain insects and other arthropods, serving as tactile organs. [1820 30; < NL < Gk kérkos tail] * * * …   Universalium

  • cercus — noun certain hair like sensory structures on some types of insects …   Wiktionary

  • cercus — 1. A stiff hairlike structure. 2. A pair of specialized sensory appendages on the 11th abdominal segment of most insects. [Mod. L., fr. G. kerkos, tail] * * * cer·cus sər kəs n, pl cer·ci sər .sī, .kī either of a pair of simple or seg …   Medical dictionary

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