Biology:Oocystis
Oocystis is a planktonic genus of mostly freshwater green algae of the family Oocystaceae.[1] It is the type genus of its family. Oocystis is mostly found in freshwater habitats and has a cosmopolitan distribution.[2] A few species are found in terrestrial, such as wet rocks, or in marine waters.[3]
Description
Oocystis is solitary or borne in colonies of two, four or eight surrounded in a thin mucilaginous envelope or mother cell wall. The colony is up to 77 μm in diameter and oval to ellipsoid. Individual cells may be fusiform, ellipsoidal, oval or nearly spherical, 7–46 μm long. The cell wall is smooth but may be thickened at the poles. Cells contain one to many parietal chloroplasts.[2]
Asexual reproduction occurs by the formation of two, four or eight autospores which are released by the rupture of the parental cell wall. Sexual reproduction and flagellated stages have not been observed in this genus.[2]
Taxonomy
The taxonomy of Oocystis is difficult and in need of revision. Species of Oocystis are distinguished based on morphological features, such as the size and shape of cells, number of chloroplasts, presence or absence of pyrenoids, and the morphology of the mucilaginous envelope.[3] Some species exhibit considerable phenotypic plasticity.[4]
In particular, the presence and absence of pyrenoids is controversial. The type species, Oocystis naegelii, has chloroplasts without pyrenoids. Some authors, such as František Hindák, separated the pyrenoid-bearing species into a separate genus, Oocystella.[2] However, other authors have stated that pyrenoids may be indistinct and difficult to observe,[5] and consider the two genera synonymous.[6]
In its current circumscription, Oocystis is paraphyletic.[7]
Ecology
Oocystis species are an important component of the biomass in freshwater habitats.[4] As primary producers, Oocystis species are often preyed on by zooplankton,[8] or parasitized by Chytridium fungi.[9] On the other hand, species like Oocystis borgei have significant allelopathic effects on Microcystis aeruginosa, a species which forms harmful algal blooms.[10]
References
- ↑ See the NCBI webpage on Oocystis. Data extracted from the "NCBI taxonomy resources". National Center for Biotechnology Information. https://ftp.ncbi.nih.gov/pub/taxonomy/.
- ↑ 2.0 2.1 2.2 2.3 Cite error: Invalid
<ref>tag; no text was provided for refs namedAlgaeBase - ↑ 3.0 3.1 Komárek, J.; Fott, B. (1983) (in German). Chlorophyceae (Grünalgen), Ordnung Chlorococcales. Das Phytoplankton des Süßwassers. E. Schweizerbart'sche Verlagsbuchhandlung. pp. 1044.
- ↑ 4.0 4.1 Stoyneva, M.P.; Cocquyt, C.; Gärtner, G.; Vyverman, W. (2007). "Oocystis lacustris Chod. (Chlorophyta, Trebouxiophyceae) in Lake Tanganyika (Africa)". Linzer biologische Beiträge 39 (1): 571–632.
- ↑ Matthews, Robin (2016). "Freshwater Algae in Northwest Washington, Volume II, Chlorophyta and Rhodophyta". A Collection of Open Access Books and Monographs (Western Washington University). doi:10.25710/fctx-n773.
- ↑ Ramos, Geraldo J. P.; De m. Bicudo, Carlos E.; Do n. Moura, Carlos Wallace (2015). "Oocystis apicurvata sp. nov. (Oocystaceae, Trebouxiophyceae), a new species of green algae from Chapada Diamantina, northeast Brazil". Brazilian Journal of Botany 38: 171–173. doi:10.1007/s40415-014-0118-6.
- ↑ Štenclová, Lenka; Fučíková, Karolina; Kaštovský, Jan; Pažoutová, Marie (2017). "Molecular and morphological delimitation and generic classification of the family Oocystaceae (Trebouxiophyceae, Chlorophyta)". Journal of Phycology 53 (6): 1263–1282. doi:10.1111/jpy.12581. PMID 28833138. Bibcode: 2017JPcgy..53.1263S.
- ↑ Kawabata, Keiichi (1988). "Ecology of Oocystis spp. in Lake Biwa: abundance, colony composition, viability, and food relations with Eodiaptomus japonicus and Daphnia longispina". Memoirs of the Faculty of Science, Kyoto University. Series of Biology 13: 41–47.
- ↑ Masters, Margaret J. (1971). "The ecology of Chytridium deltanum and other fungus parasites on Oocystis spp.". Canadian Journal of Botany 49: 75–87. doi:10.1139/b71-016.
- ↑ Wang, Xiaoqian; Zhang, Yulei; Li, Changling; Huang, Xianghu; Li, Feng; Wang, Xinyu; Li, Guanbao (2022). "Allelopathic effect of Oocystis borgei culture on Microcystis aeruginosa". Environmental Technology 43 (11): 1662–1671. doi:10.1080/09593330.2020.1847202. PMID 33151809.
Wikidata ☰ Q2024765 entry
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