barnacle


barnacle
barnacle1
barnacled, adj.
/bahr"neuh keuhl/, n.
1. any marine crustacean of the subclass Cirripedia, usually having a calcareous shell, being either stalked (goose barnacle) and attaching itself to ship bottoms and floating timber, or stalkless (rock barnacle or acorn barnacle) and attaching itself to rocks, esp. in the intertidal zone.
2. a person or thing that clings tenaciously.
[1580-85; perh. a conflation of barnacle BARNACLE GOOSE with Cornish brennyk, Ir báirneach limpet, Welsh brenig limpets, reflecting the folk belief that such geese, whose breeding grounds were unknown, were engendered from rotten ships' planking]
barnacle2
/bahr"neuh keuhl/, n.
1. Usually, barnacles. an instrument with two hinged branches for pinching the nose of an unruly horse.
2. barnacles, Brit. Dial. spectacles.
[1350-1400; ME bernacle bit, dim of bernac < OF < ?]

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Any of a majority of the 1,000 species of the subclass Cirripedia of marine crustaceans that, as adults, are covered with a shell made of hard calcium-containing plates and are permanently cemented, head down, to rocks, pilings, ships' hulls, driftwood, or seaweed or to the bodies of larger sea creatures, from clams to whales.

Barnacles trap tiny particles of food with their cirri, feathery retractable organs that emerge from openings between the shell plates. Adult barnacles commonly are hermaphrodites.

Barnacle

Anthony Mercieca, from Root Resources
EB Inc.

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also called  cirripede 
 any of more than 1,000 predominantly marine crustaceans of the subclass Cirripedia highly modified for sedentary life. There are about 850 free-living species (all marine) and about 260 species that are internal parasites of crabs and other crustaceans. A brief treatment of cirripedes follows. For full treatment, see cirripede.

      As adults, typical barnacles are covered with calcareous plates and are cemented, head down, to rocks, pilings, ships' hulls, driftwood, or seaweed, or to the bodies of larger sea creatures, from clams to whales. They trap tiny particles of food by means of cirri—feathery retractile organs formed by metamorphosis of certain of their swimming legs.

 Adult cirripedes commonly are simultaneous hermaphrodites (hermaphroditism) (that is, individuals having both male and female reproductive organs). Hermaphroditic forms sometimes have a minute, virtually formless complemental male attached to them; in the few species with separate sexes, a similar male is attached to a much larger, fully formed female. Cross-fertilization is usual, but self-fertilization does occur. The eggs mature within the mantle cavity, and the larvae emerge as free-swimming forms called nauplii, as in many other crustacean species. In typical barnacles six naupliar stages precede formation of a cypris—a nonfeeding larval stage (see video—>). The cypris has a bivalved shell of chitin (a hard protein substance), cement glands on the antennules (first antennae), and a series of thoracic legs used for swimming. The cypris eventually cements itself to a hard substrate (or invades a host) and undergoes a dramatic metamorphosis.

      Typical barnacles (order Thoracica, about 800 species) have six pairs of cirri and more or less complete shells. Pedunculate (stalked) forms include the common goose barnacle (genus Lepas), found worldwide on driftwood. Acorn barnacles, also called rock barnacles, are sessile (not stalked); their symmetrical shells tend to be barrellike or broadly conical. This group includes Balanus, responsible for much of the fouling of ships and harbour structures. Wart barnacles, such as Verruca, have asymmetrical shells.

      Burrowing barnacles (order Acrothoracica, about 30 species) are small, unisexual forms that lack shells and have fewer than six pairs of cirri. They burrow into hard limy material, such as clam shells and coral. Trypetesa is found only inside snail shells occupied by hermit crabs.

      Parasitic cirripedes of the order Rhizocephala (about 230 species), such as Sacculina, lack appendages, shell, and gut and resemble fungi. Females parasitize decapod crustaceans (crabs and allies) by sending rootlike absorptive processes through the host's body; this intrusion inhibits the host's reproductive development (parasitic castration). Parasites of the order Ascothoracica, the most primitive of cirripedes, are cyprislike as adults. An example is Laura, found imbedded in cnidarians and echinoderms.

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Universalium. 2010.

Look at other dictionaries:

  • Barnacle — Bar na*cle, n. [Prob. from E. barnacle a kind of goose, which was popularly supposed to grow from this shellfish; but perh. from LL. bernacula for pernacula, dim. of perna ham, sea mussel; cf. Gr. pe rna ham. Cf. F. bernacle, barnacle, E.… …   The Collaborative International Dictionary of English

  • Barnacle — ist die englische Bezeichnung für Rankenfußkrebse (Cirripedia) Barnacle Goose, die englische Bezeichnung der Weißwangengans (Branta leucopsis) eine Alienspezies aus Half Life ein Charakter aus dem X Men Universum Barnacle ist der Familienname… …   Deutsch Wikipedia

  • barnacle — early 13c., species of wild goose; as a type of shellfish, first recorded 1580s. Often derived from a Celtic source (Cf. Bret. bernik, a kind of shellfish), but the application to the goose predates that of the shellfish in English. The goose… …   Etymology dictionary

  • barnacle — [bär′nə kəl] n. [ME bernacle, earlier bernak < MIr bairnech & Bret bernik, kind of shellfish: ult. via Gaul * berna, split < IE base * bher , to slit] 1. BARNACLE GOOSE 2. any member of various orders of saltwater cirriped crustaceans that… …   English World dictionary

  • Barnacle — Bar na*cle, n. [See {Bernicle}.] A bernicle goose. [1913 Webster] …   The Collaborative International Dictionary of English

  • Barnacle — Bar na*cle, n. [OE. bernak, bernacle; cf. OF. bernac, and Prov. F. (Berri) berniques, spectacles.] 1. pl. (Far.) An instrument for pinching a horse s nose, and thus restraining him. Note: [Formerly used in the sing.] [1913 Webster] The barnacles …   The Collaborative International Dictionary of English

  • barnacle — index parasite Burton s Legal Thesaurus. William C. Burton. 2006 …   Law dictionary

  • barnacle — s. m. 1.  [Ornitologia] Ave aquática de arribação. 2. Ganso do mar …   Dicionário da Língua Portuguesa

  • barnacle — ► NOUN ▪ a marine crustacean which attaches itself permanently to underwater surfaces. DERIVATIVES barnacled adjective. ORIGIN Latin bernaca …   English terms dictionary

  • Barnacle — For other uses, see Barnacle (disambiguation). Barnacles Temporal range: Mid Cambrian–Recent …   Wikipedia

  • Barnacle — Créatures de Half Life Les créatures de Half Life, célèbre série de jeux vidéo, sont souvent d origine extra terrestre. Sommaire 1 Xenofaune 1.1 Écosystème 1.2 Espèces primitives 1.2.1 Barnacles …   Wikipédia en Français


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