Atractomorpha (alga): Difference between revisions
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''Atractomorpha'' consists of solitary cells. Cells are variable in size, but range from 25 μm to 6 mm in length. They are usually spindle-shaped, with two sharply pointed ends, but sometimes may develop three- or four-pointed cells. Cells are initially uninucleate (with one cell nucleus), but as the cell develops it becomes multinucleate; the cytoplasm is separated by large vacuoles into zones each containing [[chloroplast]]s and nuclei. Chloroplasts are ring-shaped bands or diffusely net-like.<ref name=Hoffman1983/> |
''Atractomorpha'' consists of solitary cells. Cells are variable in size, but range from 25 μm to 6 mm in length. They are usually spindle-shaped, with two sharply pointed ends, but sometimes may develop three- or four-pointed cells. Cells are initially uninucleate (with one cell nucleus), but as the cell develops it becomes multinucleate; the cytoplasm is separated by large vacuoles into zones each containing [[chloroplast]]s and nuclei. Chloroplasts are ring-shaped bands or diffusely net-like.<ref name=Hoffman1983/> |
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Reproduction in ''Atractomorpha'' occurs [[asexual reproduction|asexually]] or [[sexual reproduction|sexually]]. In asexual reproduction, [[zoospore]]s develop from vegetative cells, or less commonly [[aplanospore]]s. Zoospores are relatively large, initially spindle-shaped but becoming pyriform or ovate. They are biflagellate but lose their flagella after setting, at which point they develop into vegetative cells.<ref name=Hoffman1983/> In sexual reproduction, [[gametangia]] develop from vegetative cells; they may be separate male or female gametangia, or in one species, bisexual.<ref name=AlgaeBase>{{AlgaeBase genus|id=43479|name=Atractomorpha|access-date=2023-12-16}}</ref> |
Reproduction in ''Atractomorpha'' occurs [[asexual reproduction|asexually]] or [[sexual reproduction|sexually]]. In asexual reproduction, [[zoospore]]s develop from vegetative cells, or less commonly [[aplanospore]]s. Zoospores are relatively large, initially spindle-shaped but becoming pyriform or ovate. They are biflagellate but lose their flagella after setting, at which point they develop into vegetative cells.<ref name=Hoffman1983/> In sexual reproduction, [[gametangia]] develop from vegetative cells; they may be separate male or female gametangia, or in one species, bisexual.<ref name=AlgaeBase>{{AlgaeBase genus|id=43479|name=Atractomorpha|access-date=2023-12-16}}</ref> Male [[gametes]] are biflagellate,<ref name=Hoffman1983/> and female gametes are biflagellate or non-flagellate, depending on the species.<ref name=Hoffman1984/> The resulting zygotes from fertilization are initially surrounded by a thin membrane, later developing a thick wall and often an orange-red color.<ref name=Hoffman1983/> |
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Two species of ''Atractomorpha'' are known, ''[[Atractomorpha echinata]]'' and ''[[Atractomorpha porcata]]''. The two present similar vegetative cells, but can be distinguished by their reproductive characteristics. Individual cells of ''A. echinata'' typically produce either male or female gametes but not both, while cells ''A. porcata'' produces both male and female gametes.<ref name=Hoffman1984>{{cite journal|doi=10.1111/j.0022-3646.1984.00225.x |title=''Atractomorpha porcata'' sp. nov., a new membr of the Sphaeropleaceae (Chlorophyceae) from California |date=1984 |last1=Hoffman |first1=Larry R. |journal=Journal of Phycology |volume=20 |issue=2 |pages=225–236 |bibcode=1984JPcgy..20..225H |s2cid=84583201 }}</ref> Additionally, ''A. echinata'' is typically [[anisogamous]] while ''A. porcata'' is typically [[oogamous]], and their [[zygote]] walls have different ornamentations.<ref name=Hoffman1984/> |
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==Habitat== |
==Habitat== |
Revision as of 21:01, 16 December 2023
Atractomorpha | |
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Scientific classification | |
(unranked): | Viridiplantae |
Division: | Chlorophyta |
Class: | Chlorophyceae |
Order: | Sphaeropleales |
Family: | Sphaeropleaceae |
Genus: | Atractomorpha L.Hoffman |
Species | |
Atractomorpha is a genus in the Sphaeropleaceae, a family of green algae.[1] The genus name is derived from Greek and means "spindle-shaped" or "arrow-shaped",[2] and refers to the shape of the cells.[3]
Description
Atractomorpha consists of solitary cells. Cells are variable in size, but range from 25 μm to 6 mm in length. They are usually spindle-shaped, with two sharply pointed ends, but sometimes may develop three- or four-pointed cells. Cells are initially uninucleate (with one cell nucleus), but as the cell develops it becomes multinucleate; the cytoplasm is separated by large vacuoles into zones each containing chloroplasts and nuclei. Chloroplasts are ring-shaped bands or diffusely net-like.[3]
Reproduction in Atractomorpha occurs asexually or sexually. In asexual reproduction, zoospores develop from vegetative cells, or less commonly aplanospores. Zoospores are relatively large, initially spindle-shaped but becoming pyriform or ovate. They are biflagellate but lose their flagella after setting, at which point they develop into vegetative cells.[3] In sexual reproduction, gametangia develop from vegetative cells; they may be separate male or female gametangia, or in one species, bisexual.[4] Male gametes are biflagellate,[3] and female gametes are biflagellate or non-flagellate, depending on the species.[5] The resulting zygotes from fertilization are initially surrounded by a thin membrane, later developing a thick wall and often an orange-red color.[3]
Two species of Atractomorpha are known, Atractomorpha echinata and Atractomorpha porcata. The two present similar vegetative cells, but can be distinguished by their reproductive characteristics. Individual cells of A. echinata typically produce either male or female gametes but not both, while cells A. porcata produces both male and female gametes.[5] Additionally, A. echinata is typically anisogamous while A. porcata is typically oogamous, and their zygote walls have different ornamentations.[5]
Habitat
Atractomorpha has been recorded only a few times, mainly from soil isolates.[3] It occurs in shallow, temporary freshwater pools, and has been recorded from California, Texas, Australia, and Namibia.[4]
References
- ^ See the NCBI webpage on Atractomorpha. Data extracted from the "NCBI taxonomy resources". National Center for Biotechnology Information. Retrieved 2007-03-19.
- ^ Jaeger, Edmund C. (1959). A source-book of biological names and terms. Springfield, Ill: Thomas. ISBN 0-398-06179-3.
- ^ a b c d e f Hoffman, Larry R. (1983). "Atractomorpha echinata gen. et sp. nov., a new anisogamous member of the Sphaeropleaceae (Chlorophyceae)". Journal of Phycology. 19 (1): 76–86. Bibcode:1983JPcgy..19...76H. doi:10.1111/j.0022-3646.1983.00076.x. S2CID 83546430.
- ^ a b Guiry, M.D.; Guiry, G.M. "Atractomorpha". AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. Retrieved 2023-12-16.
- ^ a b c Hoffman, Larry R. (1984). "Atractomorpha porcata sp. nov., a new membr of the Sphaeropleaceae (Chlorophyceae) from California". Journal of Phycology. 20 (2): 225–236. Bibcode:1984JPcgy..20..225H. doi:10.1111/j.0022-3646.1984.00225.x. S2CID 84583201.