Brachiomonas is a genus of thalloid biflagellate green algae. These algae generally are found in marine or brackish waters, but can tolerate wide range of salinities. They may occur in freshwater pools near the sea and, occasionally, in polluted inland freshwater habitats.[2]

Brachiomonas
Plate 4; Brachiomonas simplex Hazen Drawn 29 June—4 July 1920, Aalesund, Norway.[1]
Scientific classification Edit this classification
Clade: Viridiplantae
Division: Chlorophyta
Class: Chlorophyceae
Order: Chlamydomonadales
Family: Chlamydomonadaceae
Genus: Brachiomonas
Bohlin, 1897
Species

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Description

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Brachiomonas is a single-celled, free-swimming organism. The cells have four or five large, cone-shaped projections on the equatorial region that are pointed towards the back of the cell, as well as one large cone-shaped projection on the end of the cell. In some cases, the horns may be reduced to small bumps.[3] The cell has two flagella which are about as long or longer than the cell body itself. There is a single chloroplast which fills most of the cell, with a single pyrenoid.[3] Cells sometimes have an eyespot, but lack contractile vacuoles.[4][3] One nucleus is present in the center of the cell.[5]

Asexual reproduction occurs by the successive division of the protoplast into four or eight pieces, which then form into the shape of the mother cell before being released from the mother cell wall.[3] Aplanospores have also been reported.[3] Sexual reproduction is isogamous. The gametes have two flagella, and upon fusing, form a 4-flagellate zygote.[3]

Species

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The species currently recognised are:[5]

  • B. bipyramidalis
  • B. crux
  • B. eugeniana
  • B. simplex
  • B. submarina

Species are distinguished from each other by the morphology of the "horns" of the cell, as well as the number of pyrenoids.[4][6]

References

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  1. ^ Hazen, Tracy E. (1922). "The Phylogeny of the Genus Brachiomonas". Bulletin of the Torrey Botanical Club. 49 (4): 75–92. doi:10.2307/2480203. JSTOR 2480203.
  2. ^ http://www.eol.org/pages/90532 Encyclopedia of Life. Brachiomonas.
  3. ^ a b c d e f Smith, Gilbert M. (1950). The Fresh-water Algae of the United States (2nd ed.). McGraw-Hill Book Company.
  4. ^ a b D. M. John; Brian A. Whitton; Alan J. Brook, eds. (2002). The freshwater algal flora of the British Isles: an identification guide to freshwater and terrestrial algae. Cambridge University Press. ISBN 978-0-521-77051-4.
  5. ^ a b Guiry, M.D.; Guiry, G.M. "Brachiomonas". AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. Retrieved 2023-12-24.
  6. ^ Ettl, H. (1983). Ettl, H.; Gerloff, J.; Heynig, H.; Mollenhauer, D. (eds.). Chlorophyta. 1. Teil / Part 1: Phytomonadina. Süßwasserflora von Mitteleuropa. Vol. 9. VEB Gustav Fischer Verlag. pp. XIV + 808. ISBN 978-3-8274-2659-8.