oligochaete


oligochaete
oligochaetous, adj.
/ol"i goh keet'/, n.
any of various annelids of the family Oligochaeta, including earthworms and certain small, freshwater species, having locomotory setae sunk directly in the body wall.
[1875-80; < NL Oligochaeta; see OLIGO-, CHAETA]

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      any worm of the subclass Oligochaeta (class Clitellata, phylum Annelida). About 3,500 living species are known, the most familiar of which is the earthworm (q.v.), Lumbricus terrestris. Oligochaetes are common all over the world. They live in the sea, in fresh water, and in moist soil.

      Oligochaetes, which range in length from a few millimetres (a fraction of an inch) to more than 3 m (10 feet), are notable for the absence of a head and parapodia, the flat, lobelike outgrowths used by many polychaete annelids (class Polychaeta) for locomotion. They have few setae, or bristles, on the body. Many species have a clitellum, a thickened region that secretes cocoons for enclosing eggs, which suggests a close relationship with leeches (subclass Hirudinea).

      All species are simultaneous hermaphrodites; i.e., the functional reproductive organs of both sexes occur in the same individual. Development and growth are direct, with no larval stages.

      Oligochaetes, in particular the earthworm, are ecologically important in their roles of turning over and aerating the soil; the earthworm is secondarily important as fish bait.

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Universalium. 2010.

Look at other dictionaries:

  • oligochaete — n. Any of an order of hermaphroditic terrestrial and aquatic annelids (including the earthworms) having bristles borne singly along the length of the body; a member of the {Oligochaeta}. Syn: oligochaete worm. [WordNet 1.5] …   The Collaborative International Dictionary of English

  • oligochaete — [äl′i gōkēt΄] n. [ModL Oligochaeta: see OLIGO & CHAETA] any of a class (Oligochaeta) of annelid worms, as the earthworm, lacking a definite head and having relatively few body bristles: found chiefly in moist soil and fresh water oligochaetous… …   English World dictionary

  • oligochaete — noun hermaphroditic terrestrial and aquatic annelids having bristles borne singly along the length of the body • Syn: ↑oligochaete worm • Hypernyms: ↑annelid, ↑annelid worm, ↑segmented worm • Hyponyms: ↑earthworm …   Useful english dictionary

  • oligochaete — noun Etymology: New Latin Oligochaeta, ultimately from Greek olig + chaitē long hair Date: 1896 any of a class or order (Oligochaeta) of hermaphroditic terrestrial or aquatic annelids (as an earthworm) that lack a specialized head • oligochaete… …   New Collegiate Dictionary

  • oligochaete — noun any of various hermaphroditic aquatic and terrestrial annelid worms, of the class Oligochaeta, that have single bristles along the body …   Wiktionary

  • oligochaete —   Gk oligos, few; chaete, bristle. Bristles subtending spikelets few …   Etymological dictionary of grasses

  • oligochaete — [ ɒlɪgəki:t] noun Zoology an annelid worm of the class Oligochaeta, which includes the earthworms. Origin from mod. L. Oligochaeta, from oligo + Gk khaitē long hair (taken to mean bristle ), because they have fewer setae than polychaetes …   English new terms dictionary

  • oligochaete — ol·i·go·chaete …   English syllables

  • oligochaete — ol•i•go•chaete [[t]ˈɒl ɪ goʊˌkit[/t]] n. ivt any of various annelids of the class Oligochaeta, including the earthworms, having no external sensory organs or appendages and relatively few locomotory bristles • Etymology: 1875–80; < NL… …   From formal English to slang

  • oligochaete — /ˈɒləgoʊkit/ (say oluhgohkeet) noun any of a group of annelids lacking parapodia and having locomotory setae sunk directly in the body wall. It includes earthworms and many small freshwater annelids. {New Latin oligo + Greek chaitē hair}… …   Australian English dictionary


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