Dimorphococcus

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Dimorphococcus
Dimorphococcus lunatus
Scientific classification Edit this classification
(unranked): Viridiplantae
Division: Chlorophyta
Class: Chlorophyceae
Order: Sphaeropleales
Family: Scenedesmaceae
Genus: Dimorphococcus
Braun
Species

Dimorphococcus is a genus of fresh water green algae in the family Scenedesmaceae.[1] It is found as a component of the phytoplankton of freshwater ponds, lakes, and peat bogs. It is widespread, but usually not very common.[2]

Dimorphococcus is usually found in small colonies of multiples of four cells, surrounded by a gelatinous mass. Groups of four cells are further attached to each other via mucilaginous strands, which are the remnants of the mother cell wall.[3] Cells are kidney-shaped to heart-shaped, 10–25 μm long and 3–8(–15) μm wide. Each cell is uninucleate (containing one nucleus) and has one parietal chloroplast each with one or more pyrenoids.[2]

Dimorphococcus reproduces asexually via autospores, with four spores produced per mother cell. Autospores are released through a lateral tear in the mother cell wall. After release, the empty cell wall gradually dissolves.[2]

Taxonomy[edit]

Currently, Dimorphococcus is placed in the family Scenedesmaceae, according to molecular phylogenetic analyses.[4]

One species, Dimorphococcus fritschii, is of uncertain status. The phycologist Chin Chih Jao considered it to have a different structure than other species of Dimorphococcus; accordingly, he placed it into a new genus, Dimorphococcopsis. The species has not been re-investigated and it is possible that the original placement was correct.[5]

References[edit]

  1. ^ See the NCBI webpage on Dimorphococcus. Data extracted from the "NCBI taxonomy resources". National Center for Biotechnology Information. Retrieved 2007-03-19.
  2. ^ a b c Guiry, M.D.; Guiry, G.M. "Dimorphococcus". AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. Retrieved 2023-11-24.
  3. ^ Matthews, Robin A. (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.
  4. ^ Hegewald, Eberhard; Wolf, Matthias; Keller, Alexander; Friedl, Thomas; Krienitz, Lothar (2010). "ITS2 sequence-structure phylogeny in the Scenedesmaceae with special reference to Coelastrum (Chlorophyta, Chlorophyceae), including the new genera Comasiella and Pectinodesmus". Phycologia. 49 (4): 325–335. Bibcode:2010Phyco..49..325H. doi:10.2216/09-61.1. S2CID 85145401.
  5. ^ Komárek, J.; Fott, B. (1983). Chlorophyceae (Grünalgen), Ordnung Chlorococcales. Das Phytoplankton des Süßwassers (in German). E. Schweizerbart'sche Verlagsbuchhandlung. p. 1044.

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