name = Gastrotrichs
image_width = 250px
image_caption = Darkfield photograph of a gastrotrich.
phylum = Gastrotricha
phylum_authority = Metschnikoff, 1864
subdivision_ranks = Orders
Macrodasyida ChaetonotidaThe gastrotrichs (from Greek γαστερ, "gaster" "stomach" and θριξ, "thrix" "hair") are a phylum of microscopic (0.06-3.0 mm) animals abundant in fresh water and marine environments. Most fresh water species are part of the periphytonand benthos. Marine species are found mostly interstitially in between sediment particles. They are bilaterally symmetric, with a complete gut. They demonstrate eutely, with development proceeding to a particular number of cells, and further growth coming only from an increase in cell size. The body is covered with cilia, especially about the mouth and on the ventral surface, and has two terminal projections with cement glands that serve in adhesion. This is a double-gland system where one gland secretes the glue and another secretes a de-adhesive to sever the connection. Like many microscopic animals, their locomotion is primarily powered by hydrostatics, and they reproduce entirely by parthenogenesis. Originally they were thought to have a body cavity(pseudocoel), but this was an artifact created by preservation methods, and they are now known to be acoelomate. Their relationship to other phyla is unclear. Morphology suggests that they are close to the Gnathostomulida, the Rotifera, or the Nematoda. On the other hand genetic studies place them as close relatives of the Platyhelminthes, the Ecdysozoaor the Lophotrochozoa. About 700 species have been described. The average life span of a gastrotrich is very short - about three days.
* [http://www.gastrotricha.unimore.it/overview.htm University of Modena and Reggio Emilia: Gastrotricha World Portal - Overview] - URL retrieved
December 3, 2006
* [http://www.eol.org/taxa/16100419 Gastrotrichs in "EOL"]
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Look at other dictionaries:
gastrotrich — [gas′trō trik] n. [< ModL Gastrotricha < GASTRO + tricha, ciliate creatures < Gr neut. pl. of trichos, haired < thrix (gen. trichos), hair] any of a phylum (Gastrotricha) of minute, aquatic, wormlike animals that swim by means of… … English World dictionary
gastrotrich — gastrotrichan /gas tro tri keuhn/, adj. /gas treuh trik/, n. any of the microscopic, multicellular animals of the class or phylum Gastrotricha, of fresh or salt waters, characterized by bands of cilia on the ventral surface of the bottle shaped… … Universalium
gastrotrich — noun Etymology: ultimately from Greek gastr + trich , thrix hair more at trich Date: 1940 any of a phylum (Gastrotricha) of minute aquatic pseudocoelomate animals that usually have a spiny or scaly cuticle and cilia on the ventral surface … New Collegiate Dictionary
gastrotrich — noun A microscopic aquatic animal of the phylum Gastrotricha, with a worm like body and cilia … Wiktionary
gastrotrich — gas·tro·trich … English syllables
gastrotrich — gas•tro•trich [[t]ˈgæs trə trɪk[/t]] n. ivt any tiny aquatic animal of the phylum Gastrotricha, having a long, sometimes bottle shaped body, with cilia on the underside • Etymology: 1935–40; < NL Gastrotricha < Gk gastro gastro + tricha,… … From formal English to slang
gastrotrich — /ˈgæstrətrɪk/ (say gastruhtrik) noun one of the microscopic multicellular worms belonging to the phylum Gastrotricha, having bands of cilia on the ventral side of the body … Australian English dictionary
gastrotrich — ˈgastrə.ˌtrik noun ( s) Etymology: New Latin Gastrotricha : an animal of the group Gastrotricha * * * gastrotrichan /gas tro tri keuhn/, adj. /gas treuh trik/, n. any of the microscopic, multicellular animals of the class or phylum Gastrotr … Useful english dictionary
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