Asconoid

Asconoid

Asconoid is one of three possible body plans for sponges, which form the phylum Porifera in kingdom Animalia and subkingdom Parazoa which means that they do not have a definite body shape. The asconoid body plan is characterized by a stalk-like spongocoel surrounded by a single layer of choanocytes. These choanocytes are cells that have flagella, and the flagella beat to push water through the spongocoel, creating a current. At somewhat regular intervals along the lining of the spongocoel are openings called ostia (singular, ostium). These protrude through the outer layer of the sponge (somewhat like an epidermis, but not entirely like it, since this terminology implies germ layers, which sponges do not have. Finally, at the top of the sponge is the osculum, which is the final exit for water circulating through the sponge.


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  • asconoid — /as keuh noyd /, adj. pertaining to or resembling an ascon. [ASCON + OID] * * * …   Universalium

  • asconoid — adjective (of some sponges) Lacking a definite shape …   Wiktionary

  • asconoid — as·co·noid …   English syllables

  • asconoid — adjective or noun see ascon I * * * /as keuh noyd /, adj. pertaining to or resembling an ascon. [ASCON + OID] …   Useful english dictionary

  • asconoid grade — (PORIFERA) A grade of construction in which the choanocytes line thin, short tubes; see syconoid grade, leuconoid grade or type …   Dictionary of invertebrate zoology

  • Sponge — This article is about the aquatic animal. For the porous cleaning tool, see Sponge (material). For other uses, see Sponge (disambiguation). Sponge Temporal range: Ediacaran–Recent …   Wikipedia

  • Choanocyte — Choanocytes (also known as collar cells ) are cells that line the interior of Asconoid, syconoid and leuconoid body type sponges that contain a central flagellum surrounded by a collar of microvilli which are connected by a thin membrane. It is… …   Wikipedia

  • synconoid grade — (PORIFERA) A grade of construction intermediate between the asconoid and the leuconoid, in which each radial canal is subdivided into elongate flagellate chambers grouped around a common excurrent channel; see leuconoid grade, asconoid grade …   Dictionary of invertebrate zoology

  • Choanoderm — The choanoderm is composed of flagellated collar cells, or choanocytes. The sponge body is mostly a connective tissue, the mesohyl, over which are applied epithelioid monolayers of cells, the outer pinacoderm and the inner choanoderm. Most… …   Wikipedia

  • Calcareous sponge — Taxobox name = Calcareous sponges image caption = Calcispongiae from Ernst Haeckel s Kunstformen der Natur , 1904 regnum = Animalia phylum = Porifera classis = Calcarea classis horny = Bowerbank, 1864 subdivision ranks = Orders subdivision =… …   Wikipedia

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