Planula

Planula

A planula is the free-swimming, flattened, ciliated, bilaterally symmetric larva of a jellyfish, a hydrozoan cnidarian, or a ctenophore. Depending on the species, the planula either metamorphosises into a miniature version of the adult form (such as some jellyfish and all ctenophores), or navigates through the water until it reaches a hard substrate (some may prefer specific substrates) where it anchors and grows into a polyp. Planulae of Medusozoa have no mouth or digestive tract and are unable to feed themselves, while those of Anthozoa can feed.


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  • planula — [planyla] ou planule [planyl] n. f. ÉTYM. 1874, planula, trad. de Haeckel; lat. planula, dimin. de planus « plat ». ❖ ♦ Zool. Larve aplatie de certaines méduses. || La planule peut se fixer et donne naissance à une hydraire d où bourgeonnent de… …   Encyclopédie Universelle

  • Planula — Plan u*la, n.; pl. {Planul[ae]}. [L., a little plane.] 1. (Biol.) In embryonic development, a vesicle filled with fluid, formed from the morula by the divergence of its cells in such a manner as to give rise to a central space, around which the… …   The Collaborative International Dictionary of English

  • Planŭla — Planŭla, Flimmerlarve der Cölenteraten, s. Entwickelungsgeschichte, S. 845, u. Hydromedusen, S. 696 …   Meyers Großes Konversations-Lexikon

  • Planula — Planula, aus Vorstadien hervorgehende, bewimperte Larve der Cnidaria (Nesseltiere); entspricht einer Gastrula und enthält oftmals keinen Hohlraum, sondern massives Entoderm …   Deutsch wörterbuch der biologie

  • planula — plànula ž <G ē> DEFINICIJA zool. ličinka žarnjaka; tjelesna stijenka sastoji se od dvaju slojeva stanica, pliva pomoću trepetljika ETIMOLOGIJA lat …   Hrvatski jezični portal

  • planula — [plan′yo͞o lə] n. pl. planulae [plan′yo͞olē΄] [ModL < LL, little plane, dim. < L planus, flat: see PLAIN1] the ciliated larva of a cnidarian planuloid [plan′yo͞oloid΄] adj …   English World dictionary

  • Planula — Die Planula oder Planulalarve ist eine Larvenform der Nesseltiere (Cnidaria). Sie bildet sich durch Gastrulation der Blastula, ist zweischichtig (Ektoderm und Entoderm) und bewimpert. Der Mund (Blastoporus) wird meist direkt nach der Bildung… …   Deutsch Wikipedia

  • Planula — Pla|nu|la 〈f. 10〉 bewimperter Keim der Hohltiere, der Gastrula entsprechend [neulat., Fem. zu planulus, Verkleinerungsform zu lat. planus „eben, flach“] * * * Planula   [zu lateinisch planus »eben«, »flach«] die, /...len und ...lae, Planula|larve …   Universal-Lexikon

  • Planula — Cycle de vie d un scyphozoaire de la larve planula à la forme méduse. La planula, ou planaire, est la larve ciliée, aplatie, à symétrie bilatérale et nageant librement, qui résulte de la fécondation d un gamète femelle par un gamète mâle chez… …   Wikipédia en Français

  • planula — planular, planulate /plan yeuh layt /, adj. /plan yeuh leuh/, n., pl. planulae / lee /. Zool. the ciliate, free swimming larva of a coelenterate. [1865 70; < NL, dim. of L planum something flat. See PLANE1, ULE] * * * ▪ zoology plural  planulae …   Universalium

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