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Ascus (bryozoa)
The ascus is a diagnostic morphological feature of the bryozoan suborder Ascophora (hence the name of the suborder). It is a water-filled sac of frontal membrane opening (ascopore) at or near the zooid orifice. It functions as a hydrostatic system by allowing water into the space below the inflexible, calcified frontal wall (covering their whole frontal surface apart from the orifice) when the zooid everts its polypide The polypide in bryozoans encompasses most of the organs and tissues of each individual zooid A zooid or zoöid is a single animal that is part of a colonial animal. This lifestyle has been adopted by animals from separate unrelated taxa. ... (feeding tentacles) by muscles pulling the frontal membrane inwards (non-ascophoran cheilostomes do not need this structure as their frontal wall is not calcified and thus flexible). The ascus, along with a calcified frontal shield, define ascophoran bryozoa. References Cheilostomatida Protostome anatomy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morphology (biology)
Morphology is a branch of biology dealing with the study of the form and structure of organisms and their specific structural features. This includes aspects of the outward appearance (shape, structure, colour, pattern, size), i.e. external morphology (or eidonomy), as well as the form and structure of the internal parts like bones and organs, i.e. internal morphology (or anatomy). This is in contrast to physiology, which deals primarily with function. Morphology is a branch of life science dealing with the study of gross structure of an organism or taxon and its component parts. History The etymology of the word "morphology" is from the Ancient Greek (), meaning "form", and (), meaning "word, study, research". While the concept of form in biology, opposed to function, dates back to Aristotle (see Aristotle's biology), the field of morphology was developed by Johann Wolfgang von Goethe (1790) and independently by the German anatomist and physiologist Karl Friedrich Burdach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bryozoa
Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about long, they have a special feeding structure called a lophophore, a "crown" of tentacles used for filter feeding. Most marine bryozoans live in tropical waters, but a few are found in oceanic trenches and polar waters. The bryozoans are classified as the marine bryozoans (Stenolaemata), freshwater bryozoans (Phylactolaemata), and mostly-marine bryozoans (Gymnolaemata), a few members of which prefer brackish water. 5,869living species are known. At least two genera are solitary (''Aethozooides'' and ''Monobryozoon''); the rest are colonial. The terms Polyzoa and Bryozoa were introduced in 1830 and 1831, respectively. Soon after it was named, another group of animals was discovered whose filtering mechanism looked similar, so it was included in Bryozoa until 1869, when the two groups were no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascophora
Ascophora is an infraorder under order Cheilostomatida of the Bryozoa. They are now considered a synonym of Flustrina. Ascophorans are distinguished from other cheilostomes in having a completely calcified wall covering their frontal surface apart from the orifice, and possessing an ascus (hence the name of the suborder). The ascus is a water-filled sac of frontal membrane opening at or near the orifice. It functions as a hydrostatic system by allowing water into the space below the inflexible frontal wall when the zooid everts its polypide (feeding tentacles) by muscles pulling the frontal membrane inwards (non-ascophorans do not need this structure as their frontal wall is not calcified). The structure of this frontal wall is the basis of distinguishing the four major subdivisions of the Ascophora, each of which is, however, currently under suspicion of being polyphyletic and/or paraphyletic.Gordon, D.P. 2000. Towards a phylogeny of cheilostomes - morphological models of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polypide
The polypide in bryozoans encompasses most of the organs and tissues of each individual zooid. This includes the tentacles, tentacle sheath, U-shaped digestive tract, musculature and nerve cells. It is housed in the zooidal exoskeleton, which in cyclostomes Cyclostome is a biological term (from the Greek for "round mouth") used in a few different senses: * for the taxon Cyclostomi, which comprises the extant jawless fishes: the hagfish (Myxini) and the lampreys (Petromyzontidae). This was thought fo ... is tubular and in cheilostomes is box-shaped. See also Bryozoan Anatomy References Bryozoology Protostome anatomy {{bryozoan-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cheilostomata
Cheilostomatida, also called Cheilostomata, is an order of Bryozoa in the class Gymnolaemata. They are exclusively marine, colonial invertebrate animals. Cheilostome colonies are composed of calcium carbonate and grow on a variety of surfaces, including rocks, shells, seagrass and kelps. The colony shapes range from simple encrusting sheets to erect branching and even unattached forms. As in other bryozoan groups, each colony is composed of a few to thousands of individual polypides. Each individual has a U-shaped gut, and no respiratory, circulatory, or nerve system. Unique among bryozoans, cheilostome polypides are housed in a box-shaped zooids, which do not grow larger once the zooid is mature. The opening through which the polypide protrudes is protected by a calcareous or chitinous lidlike structure, an operculum. Cheilostomes possess avicularia, which have modified the operculum into a range of mandibles (possibly for defense) or hair-like setae (possibly for cleaning). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cheilostomatida
Cheilostomatida, also called Cheilostomata, is an order of Bryozoa in the class Gymnolaemata. They are exclusively marine, colonial invertebrate animals. Cheilostome colonies are composed of calcium carbonate and grow on a variety of surfaces, including rocks, shells, seagrass and kelps. The colony shapes range from simple encrusting sheets to erect branching and even unattached forms. As in other bryozoan groups, each colony is composed of a few to thousands of individual polypides. Each individual has a U-shaped gut, and no respiratory, circulatory, or nerve system. Unique among bryozoans, cheilostome polypides are housed in a box-shaped zooids, which do not grow larger once the zooid is mature. The opening through which the polypide protrudes is protected by a calcareous or chitinous lidlike structure, an operculum. Cheilostomes possess avicularia, which have modified the operculum into a range of mandibles (possibly for defense) or hair-like setae (possibly for cleaning). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
