Unreferenced stub auto yes date December 2009 merge Sponge discuss Talk Sponge Body plan date February 2010 Asconoid is one of three possible body plans for sponge s, 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 choanocyte s. These choanocytes are cells that have flagella , and the flagella beat to push water through the spongocoel, creating a Ocean current current . At somewhat regular intervals along the lining of the spongocoel are openings called Sponge ostia singular, ostium . These protrude through the outer layer of the sponge somewhat like an Squamous epithelium epidermis , but not entirely like it, since this terminology implies germ layer s, 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. This single layer of choanocytes limits the size of asconoids, with the largest having a diameter of only 1 mm. This is due to the surface area mass ratio which would not allow an asconoid sponge of larger size sufficient nutrition. References reflist Category Sponge anatomy Sponge stub Animal anatomy stub fr ascono de pl Askon sr ... more details
unreferenced date June 2010 expert date June 2010 The choanoderm is composed of flagellated collar cells, or choanocyte s. The sponge body is mostly a connective tissue , the mesohyl , over which are applied epithelium epithelioid monolayer s of cell biology cells , the outer pinacoderm and the inner choanoderm. Most aspects of sponge biology, including feeding, reproduction, and gas exchange, depend on a low pressure flow of water generated by the flagella of the choanoderm. Three grades of organization, asconoid , syconoid , and leuconoid , reflect the degree of elaboration of the choanoderm layer and mesohyl. In the asconoid plan the interior water space, or Atrium architecture atrium , is large and unpartitioned. In the syconoid plan the periphery of the atrium is divided into numerous small flagellated chambers with increased surface area for choanocytes. In leuconoid sponges the atrium is replaced by a proliferation of mesohyl and a complex network of water channels and flagellated chambers. References reflist Category Sponge anatomy ... more details
Unreferenced stub auto yes date December 2009 A spongocoel IPAc en icon s p s i l is the large, central cavity of sponge s. Water enters the spongocoel through hundreds of tiny pores Ostium Ostia and exits through the larger opening osculum . Depending on the body plan of the sponge which can be asconoid , syconoid , or leuconoid , the spongocoel could be a simple interior space of the sponge or a complexly branched inner structure. Regardless of body plan or class, the spongocoel is lined with choanocyte s, which have flagella that push water through the spongocoel, creating a Fluid dynamics current . References reflist Category Sponge anatomy Sponge stub Animal anatomy stub fr Spongocoele pl Spongocel pt Esponjocele sr ... more details
Taxobox name Clathrinida image Clathrina clathrus Scarpone 055.jpg image width 220px image caption Clathrina clathrus regnum Animalia phylum Porifera classis Calcarea subclassis Calcinea ordo Clathrinida ordo authority Hartman, 1958 subdivision ranks Families subdivision Clathrinidae br Soleneiscidae br Levinellidae br Leucaltidae br Leucascidae br Leucettidae wikispecies Clathrinida Clathrinida is an order biology order of Calcinea . Members of this order have calcareous skeletons, and are strictly marine. These sponges have an asconoid structure and lack a true dermal membrane or cortex anatomy cortex . The spongocoel is lined with choanocytes . External links http www.marinespecies.org porifera porifera.php?p taxdetails&id 131593 Category Poriferans Category Clathrinida sponge stub fr Clathrinida it Clathrinida pl Clathrinida pt Clathrinida ru Clathrinida ... more details
Refimprove date December 2009 Choanocytes also known as collar cells are cell biology cell s that line the interior of Asconoid , syconoid and leuconoid body type sea sponge sponges that contain a central flagellum surrounded by a collar of microvilli which are connected by a thin membrane. It is the closest family member to the free living ancestor called choanoflagellate . The flagellae beat regularly, creating a water flow across the microvilli which can then filter feeder filter nutrients and other food from the water taken from the collar of the sponge. Food particles are then phagocytosed by the cell. ref Anderson, D. 2001 Invertebrate Zoology Oxford University Press ref Location Choanocytes are found dotting the surface of the spongocoel in asconoid sponges and the radial canals in syconoid sponges , but they comprise entirely the chambers in leuconoid sponges. Function By cooperatively moving their flagella, choanocytes generate a flow of water through the sponges pores, into the spongocoel , and out through the osculum . This improves both respiratory and digestive functions for the sponge, pulling in oxygen and nutrients and allowing a rapid expulsion of carbon dioxide and other waste products. Although all cells in a sponge are capable of living on their own, choanocytes carry out most of the sponge s ingestion, passing digested materials to the amoebocytes for delivery to other cells. Choanocytes can also turn into spermatocyte s when needed for sexual reproduction, due to the lack of reproductive organs in sponges amoebocytes become the oocyte s . Evolutionary Significance They bear more than a passing resemblance to Choanoflagellates , and demonstrate key steps in the evolution of animals. Scientist Nicole King helped to establish the distinction. ref Shubin, Neil Your Inner Fish ref DNA sequencing indicates that multicellular choanoflagellates and poriferans are sister groups, both descended from the same eukaryotic clade. One can see modern choanofla ... more details
Automatic taxobox taxon Calcarea name Calcareous sponges image Haeckel Calcispongiae.jpg image caption Calcispongiae from Ernst Haeckel s Kunstformen der Natur , 1904 authority James Scott Bowerbank Bowerbank , 1817 subdivision ranks Subclasses subdivision Calcinea br Calcaronea The calcareous sponges of Class biology class Calcarea are members of the animal phylum Porifera , the cellular sponges. They are characterized by spicules made out of calcium carbonate in the form of calcite or aragonite . While the spicules in most species have three points, in some species they have either two or four points. Biology File Clathrina clathrus Scarpone 055.jpg thumb left Clathrina clathrus , an asconoid calcareous sponge All sponges in this class are strictly marine, and, while they are distributed worldwide, most are found in shallow tropical waters. Like all other sponges, they are sedentary filter feeders. All three sponge body plans are represented within class Calcarea asconoid , syconoid , and leuconoid . Typically, calcareous sponges are small, measuring less than convert 10 cm in in height, and drab in colour. However, a few brightly coloured species are also known. Calcareous sponges vary from radially symmetrical vase shaped body types to colonies made up of a meshwork of thin tubes, or irregular massive forms. The skeleton has either a mesh or honeycomb structure. Classification Of the 15,000 or so species of Porifera that exist, only 400 of those are Calcareans. Calcarean sponges first appeared during the Cambrian and their diversity was greatest during the Cretaceous Cretaceous period . Recent molecular analysis suggests that the class Calcarea should be designated as a phylum , in particular the first to have diverged in the Animal Kingdom Animalia the other sponges belong to the phylum Silicarea . The calcareous sponges are divided into two subclasses and seven orders Class Calcarea Subclass Calcinea Order Clathrinida Order Leucettida Order Murrayonida Subclas ... more details
in sponges is a tube or vase shape known as asconoid , but this severely limits the size of the animal ... food and oxygen depends on the area covered by choanocytes. Asconoid sponges seldom exceed ... Calcite br May be individual or large masses Never Common. br Made of calcite if present. Asconoid ... have three body types asconoid , syconoid , and leuconoid . Choanocyte s also known as collar cells ... more details
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