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Characium

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Characium
Characium hookeri
Scientific classification Edit this classification
Clade: Viridiplantae
Division: Chlorophyta
Class: Chlorophyceae
Order: Sphaeropleales
Family: Characiaceae
Genus: Characium
A. Braun in Kützing, 1849
Type species
Characium sieboldii
Species[1]

See text

Characium is a genus of green algae in the family Characiaceae.[1] It is very commonly found in freshwater habitats, where it is attached to phytoplankton or zooplankton.[2]

Description

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Characium consists of single or rarely clustered cells. They are attached to a plant or animal substrate (thus epiphytic or epizoic), via a stalk or a circular pad. The cells have diverse shapes, ranging from fusiform to club-shaped or spherical, and are variously straight, hooked, or S-shaped. Cells usually contain a single parietal chloroplast filling the cell, with a central pyrenoid. In some species, the chloroplasts fragment into multiple plastids, each with one pyrenoid.[3] Mature cells have one nucleus (are uninucleate).[4]

Characium reproduces asexually by zoospores. Zoospores have two flagella.[3]

Identification

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The genus Characium is similar to Characiopsis, a type of algae in the class Eustigmatophyceae. The two genera are very similar and have been confused in the past;[5] however, Characium produces starch to store excess carbon and thus stains brown to purple in Lugol's iodine solution, while Characiopsis does not.[6] Many other similar segregate genera have been named. These include Deuterocharacium, which differs in having chloroplasts without pyrenoids,[7] and Characiopodium, with multinucleate mature cells.[4]

Identification of species depends on the shapes and sizes of the cell body, as well as the stipe with which the body is attached.[1]

Species list

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References

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  1. ^ a b c Guiry, M.D.; Guiry, G.M. "Characium". AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. Retrieved 2023-09-26.
  2. ^ Shubert, Elliot; Gärtner, Georg (2014). "Chapter 7. Nonmotile Coccoid and Colonial Green Algae". In Wehr, John D.; Sheath, Robert G.; Kociolek, J. Patrick (eds.). Freshwater Algae of North America: Ecology and Classification (2 ed.). Elsevier Inc. ISBN 978-0-12-385876-4.
  3. ^ a b Bicudo, Carlos E. M.; Menezes, Mariângela (2006). Gêneros de Algas de Águas Continentais do Brasil: chave para identificação e descrições (2 ed.). RiMa Editora. p. 508. ISBN 857656064X.
  4. ^ a b Ettl, Hanuš; Gärtner, Georg (2013). Syllabus der Boden-, Luft- und Flechtenalgen (in German) (2nd ed.). Springer-Verlag. ISBN 9783642394614.
  5. ^ Guiry, M.D.; Guiry, G.M. "Characiopsis". AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. Retrieved 2023-09-26.
  6. ^ 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.
  7. ^ Guiry, M.D.; Guiry, G.M. "Deuterocharacium". AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. Retrieved 2023-10-09.