Difference between revisions of "Entoprocta" - New World Encyclopedia
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[[Pedicellinidae]] | [[Pedicellinidae]] | ||
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| − | '''Entoprocta''' is a [[phylum (biology)|phylum]] of small aquatic, largely marine, filter-feeding [[invertebrate]]s that are characterized by having | + | '''Entoprocta''' is a [[phylum (biology)|phylum]] of small aquatic, largely marine, filter-feeding [[invertebrate]]s that are characterized by having [[tentacle]]s with a downstream-collecting ciliary system and without coelomic canals, and that have their [[anus]] inside the ring of tentacles. They range in size from only about 0.5 millimeters to 5.0 millimeters (0.02-0.2 inches). They are known as '''entoprocts''', '''goblet worms''', and '''kamptozoans'''. |
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| + | The phylum includes about 150 species in several families. While most species are marine, there is one [[freshwater]] genus, | ||
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| + | and the freshwater species ''[[Urnatella gracilis]]'' is widespread. | ||
==Overview and description== | ==Overview and description== | ||
| + | Entoprocts were originally grouped together with the [[ectoprocts]] in the phylum Bryozoa. Both are tiny, aquatic, filter feeding organisms, and are characterized by a lophophore. The lophophore is essentially a ciliated ribbon or string (Luria et al. 1981), which is either a horseshoe-shaped or circular extension that surrounds the mouth (Smithsonian 2007). However, despite these similarities, it has come to be realized that the entoprocts and ectoprocts are very distinct and unrelated phyla (Thorp and Covich 2001). | ||
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| + | One notable distinction between members of Endoprocta and those of Ectoprocta is that the ectoprocts have their anus outside their ring of tentacles, whereas the endoprocts have their anus inside the space enclosed by their tentacles (Ramel 2008). Other distinctions include ** | ||
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| + | '''Bryozoa''', also known as '''Ectoprocta''', is a major [[invertebrate]] [[Taxonomy#Scientific or biological classification|phyla]], whose members, the '''bryozoans''', are tiny, aquatic, and mostly sessile and colonial animals. Also known as '''moss animals''' or '''sea mats''', bryozoans generally build stony [[skeleton]]s of [[calcium carbonate]], superficially similar to [[coral]]. | ||
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| + | Bryozoa and Ectoprocta are generally considered synonymous, but historically Ectoprocta was considered one of two subgroups within Bryozoa, the other being Entoprocta, which most systematics now separate into its own phyla. However, some biologists still consider Ectoprocta and Entoprocta as subgroups within the larger grouping Bryozoa, whether or not they are accorded status as a sub-phyla or a phyla. The members are still known as bryozoans regardless if the phyla is known as Ectoprocta. | ||
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| + | Bryozoans have a distinctive feeding organ called a lophophore found only in two other animal phyla, [[Phoronida]] (phoronid worms) and [[Brachiopoda]] (lamp shells). The | ||
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| + | The Bryozoans were formerly considered to contain two subgroups: the [[Ectoprocta]] and the [[Entoprocta]], based on the similar bodyplans and mode of life of these two groups. (Some researchers also included the Cycliophora, which are thought to be closely related to the Entoprocta.) However, the Ectoprocta are coelomate (possessing a body cavity) and their embryos undergo [[radial cleavage]], while the Entoprocta are acoelemate and undergo spiral cleavage. Molecular studies are ambiguous about the exact position of the Entoprocta, but do not support a close relationship with the Ectoprocta. For these reasons, the Entoprocta are now considered a phylum of their own (Valentine 2004). The removal of the 150 species of Entoprocta leaves Bryozoa synonymous with Ectoprocta; some authors have adopted the latter name for the group, but the majority continue to use the former. | ||
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They have a [[lophophore]], and as their name suggests, are distinguished from other [[lophophorate]]s by the position of the [[anus]] inside the ring of cilia rather than outside. | They have a [[lophophore]], and as their name suggests, are distinguished from other [[lophophorate]]s by the position of the [[anus]] inside the ring of cilia rather than outside. | ||
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Entoprocts can reproduce either by budding, or sexually. They are unusual in being sequential [[hermaphrodite]]s. | Entoprocts can reproduce either by budding, or sexually. They are unusual in being sequential [[hermaphrodite]]s. | ||
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==Notes== | ==Notes== | ||
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http://icb.oxfordjournals.org/cgi/content/full/42/3/685 | http://icb.oxfordjournals.org/cgi/content/full/42/3/685 | ||
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1056 pages | 1056 pages | ||
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Family Barentsiidae | Family Barentsiidae | ||
Revision as of 23:42, 17 October 2008
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 Barentsia discreta
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Barentsiidae (Urnatellidae) |
Entoprocta is a phylum of small aquatic, largely marine, filter-feeding invertebrates that are characterized by having tentacles with a downstream-collecting ciliary system and without coelomic canals, and that have their anus inside the ring of tentacles. They range in size from only about 0.5 millimeters to 5.0 millimeters (0.02-0.2 inches). They are known as entoprocts, goblet worms, and kamptozoans.
The phylum includes about 150 species in several families. While most species are marine, there is one freshwater genus,
and the freshwater species Urnatella gracilis is widespread.
Overview and description
Entoprocts were originally grouped together with the ectoprocts in the phylum Bryozoa. Both are tiny, aquatic, filter feeding organisms, and are characterized by a lophophore. The lophophore is essentially a ciliated ribbon or string (Luria et al. 1981), which is either a horseshoe-shaped or circular extension that surrounds the mouth (Smithsonian 2007). However, despite these similarities, it has come to be realized that the entoprocts and ectoprocts are very distinct and unrelated phyla (Thorp and Covich 2001).
One notable distinction between members of Endoprocta and those of Ectoprocta is that the ectoprocts have their anus outside their ring of tentacles, whereas the endoprocts have their anus inside the space enclosed by their tentacles (Ramel 2008). Other distinctions include **
Bryozoa, also known as Ectoprocta, is a major invertebrate phyla, whose members, the bryozoans, are tiny, aquatic, and mostly sessile and colonial animals. Also known as moss animals or sea mats, bryozoans generally build stony skeletons of calcium carbonate, superficially similar to coral.
Bryozoa and Ectoprocta are generally considered synonymous, but historically Ectoprocta was considered one of two subgroups within Bryozoa, the other being Entoprocta, which most systematics now separate into its own phyla. However, some biologists still consider Ectoprocta and Entoprocta as subgroups within the larger grouping Bryozoa, whether or not they are accorded status as a sub-phyla or a phyla. The members are still known as bryozoans regardless if the phyla is known as Ectoprocta.
Bryozoans have a distinctive feeding organ called a lophophore found only in two other animal phyla, Phoronida (phoronid worms) and Brachiopoda (lamp shells). The
The Bryozoans were formerly considered to contain two subgroups: the Ectoprocta and the Entoprocta, based on the similar bodyplans and mode of life of these two groups. (Some researchers also included the Cycliophora, which are thought to be closely related to the Entoprocta.) However, the Ectoprocta are coelomate (possessing a body cavity) and their embryos undergo radial cleavage, while the Entoprocta are acoelemate and undergo spiral cleavage. Molecular studies are ambiguous about the exact position of the Entoprocta, but do not support a close relationship with the Ectoprocta. For these reasons, the Entoprocta are now considered a phylum of their own (Valentine 2004). The removal of the 150 species of Entoprocta leaves Bryozoa synonymous with Ectoprocta; some authors have adopted the latter name for the group, but the majority continue to use the former.
They have a lophophore, and as their name suggests, are distinguished from other lophophorates by the position of the anus inside the ring of cilia rather than outside.
(Gr. εντος, entos inside + προκτος, proktos anus)
Entoprocts are filter feeders, their tentacles secreting a mucus that catches food particles, which is then moved towards the mouth by cilia on the tentacles. Nearly all species are sedentary, attached to the substrate by a stalk, with the body being cup-shaped. Some species are colonial, with multiple animals on branching systems of stalks.
Entoprocts can reproduce either by budding, or sexually. They are unusual in being sequential hermaphrodites.
Notes
http://icb.oxfordjournals.org/cgi/content/full/42/3/685 Integrative and Comparative Biology 2002 42(3):685-691; doi:10.1093/icb/42.3.685 © 2002 by The Society for Integrative and Comparative Biology The Phylogenetic Position of Entoprocta, Ectoprocta, Phoronida, and Brachiopoda1 Claus Nielsen2
- Luria, S. E., S. J. Gould, and S. Singer. 1981. A View of Life. Menlo Park, CA: Benjamin/Cummings Publishing Company. ISBN 0805366482
- Ramel, G. 2005. The Phylum Ectoprocta (Bryozoa). Earth Life Web. Retrieved December 17, 2007.
- What is a bryozoan. Smithsonian Marine Station at Fort Pierce, 2007. Retrieved February 13, 2007.
- Waggoner, B., and A. G. Collins. 1999. Bryozoa: Life history and ecology. University of California Museum of Paleontology. Retrieved February 13, 2007.
Ecology and Classification of North American Freshwater Invertebrates By James H. Thorp, Alan P. Covich Contributor James H. Thorp Published by Academic Press, 2001 ISBN 0126906475, 9780126906479 1056 pages
Family Barentsiidae
- Genus Barentsia
- Genus Pedicellinopsis
- Genus Pseudopedicellina
- Genus Coriella
- Genus Urnatella
Family Loxokalypodidae
- Genus Loxokalypus
Family Loxosomatidae
- Genus Loxosoma
- Genus Loxosomella
- Genus Loxomitra
- Genus Loxosomespilon
- Genus Loxocore
Family Pedicellinidae
- Genus Pedicellina
- Genus Myosoma
- Genus Chitaspis
- Genus Loxosomatoides
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