Yellow-green algae

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Yellow-green algae
Alger, Botydium granulatum, Nordisk familjebok.png
Botydium granulatum
Scientific classification
Domain: Eukaryota
Kingdom: Chromalveolata
Phylum: Heterokontophyta
Class: Xanthophyceae
Allorge, 1930,[1] emend. Fritsch, 1935[2]
Synonyms
  • Heterokontae Luther, 1899[3]
  • Tribophyceae Hibberd, 1981[4]
  • Heteromonadida Leedale, 1983[5]
  • Xanthophyta Hibberd, 1990[6]

Yellow-green algae or xanthophytes are an important group of heterokont algae. Most live in freshwater, but some are found in marine and soil habitats. They vary from single-celled flagellates to simple colonial and filamentous forms. Xanthophyte chloroplasts contain the photosynthetic pigments Chlorophyll a, Chlorophyll c, β-Carotene, and the carotenoid diadinoxanthin.[7] Unlike other heterokonts, their chloroplasts do not contain fucoxanthin, which accounts for their lighter colour. Its storage polysaccharide is chrysolaminarin.[7] Xanthophyte cell walls are produced of cellulose and hemicellulose.[7] They appear to be the closest relatives of the brown algae.

Classifications[edit]

The species now placed in Xanthophyceae were formerly included in the Chlorophyceae.[8] In 1899, Luther created the group Heterokontae for green algae with unequal flagella. Pascher (1914) included the Heterokontae in Chrysophyta. In 1930, Allorge renamed the group as Xanthophyceae.

Xanthophyceae have been divided into the following four orders in some classification systems:[citation needed]

Fritsch (1935)[edit]

Fritsch (1935)[10] recognizes the following orders in the class Xanthophyceae:

  • Order Heterochloridales
    • Suborder Heterochlorineae
    • Suborder Heterocapsineae
    • Suborder Heterodendrineae
    • Suborder Heterorhizidineae
  • Order Heterococcales
  • Order Heterotrichales
  • Order Heterosiphonales

Smith (1938)[edit]

In the classification of Smith (1938), there are six orders in the class Xanthophyceae, placed in the division Chrysophyta:

Pascher (1939)[edit]

Pascher (1939) recognizes 6 classes in Heterokontae:[11]

  • Class Heterochloridineae
  • Class Rhizochloridineae
  • Class Hetcrocapsineae
  • Class Heterococcincae
  • Class Hetcrotrichineae
  • Class Heterosiphonineae

Ettl (1978), van den Hoek et al. (1995)[edit]

In a classification presented by van den Hoek, Mann and Jahns (1995), based on the level of organization of the thallus, there are seven orders:

These are the same orders of the classification of Ettl (1978)[12], an updated version of the classic work by Pascher (1939). Ultrastructural and molecular studies shows that the Mischococcales might be paraphyletic, and the Tribonematales and Botrydiales polyphyletic,[13] and suggests two orders at most be used until the relationships within the division are sorted.[14]

Maistro et al. (2009)[edit]

Informal groups, according to Maistro et al. (2009):[15]

  • Botrydiopsalean clade
  • Chlorellidialean clade
  • Tribonematalean clade
  • Vaucherialean clade

Unicellular flagellates, amoeboid and palmelloid taxa were not included in this study.

Adl et al. (2005, 2012)[edit]

According to Adl et al. (2005, 2012):[14][16]

  • Tribonematales (genera Botrydium, Bumilleriopsis, Characiopsis, Chloromeson, Heterococcus, Ophiocytium, Sphaerosorus, Tribonema, Xanthonema)
  • Vaucheriales (genus Vaucheria)

See also[edit]

References[edit]

  1. ^ Allorge, P. (1930). Heterocontées ou Xanthophycées? Rev. Alg. 5: 230.
  2. ^ Fritsch, F.E. (1935) The Structure and Reproduction of the Algae. Volume I. Introduction, Chlorophyceae, Xanthophyceae, Chrysophyceae, Bacillariophyceae, Cryptophyceae, Dinophyceae, Chloromonadineae, Euglenineae, Colourless Flagellata. Cambridge University Press, Cambridge.[page needed]
  3. ^ Lüther, A. (1899). "Über Chlorosaccus eine neue Gattung der Süsswasseralgen". Bihang til Kongliga Svenska Vetenskaps-Akademiens Handlingar 24: 1–22. OCLC 178060545. 
  4. ^ Hibberd, D. J. (February 1981). "Notes on the taxonomy and nomenclature of the algal classes Eustigmatophyceae and Tribophyceae (synonym Xanthophyceae)". Botanical Journal of the Linnean Society 82 (2): 93–119. doi:10.1111/j.1095-8339.1981.tb00954.x. 
  5. ^ Leedale, G.F. (1985). "Order 5, Heteromonadida Leedale, 1983". In Lee, John J.; Hutner, Seymour Herbert; Bovee, Eugene C. An illustrated Guide to Protozoa. Lawrence, Kansas: Society of Protozoologists. pp. 70–. [page needed]
  6. ^ Hiberd, D. J. (1990). "Phylum Xanthophyta". In Margulis, L.; Corliss, J. O.; Melkonian, M. et al. Handbook of Protoctista. Boston, Massachusetts, USA: Jones and Bartlett Publishers. pp. 686–97. 
  7. ^ a b c Stace, Clive A. (1991). Plant Taxonomy and Biosystematics. Cambridge University Press. ISBN 978-0-521-42785-2. [page needed]
  8. ^ Chapman, V. J. An Introduction to the Study of Algae. University Press, Cambridge; The Macmillan Company, New York, 1941, p. 18, [1].
  9. ^ Christensen, T. 1987. Seaweeds of the British Isles. Volume 4 Tribophyceae (Xanthophyceae). British Museum (Natural History), London ISBN 0-565-00980-X[page needed]
  10. ^ Fritsch, F.E. (1935) The Structure and Reproduction of the Algae. Volume I. Introduction, Chlorophyceae. Xanthophyceae, Chrysophyceae, Bacillariophyceae, Cryptophyceae, Dinophyceae, Chloromonadineae, Euglenineae, Colourless Flagellata. Vol. I, Cambridge University Press, Cambridge, [2].
  11. ^ Pascher, A., 1939. Heterokonten. In: Rabenhorsts Kryptogamen-Flora von Deutschland, Österreich und der Schweiz. Aufl. 2 Bd. XI. Leipzig: Akad. Verlagsges (1937–1939). p. 204, [3].
  12. ^ Ettl, H., 1978. Xanthophyceae. In: Ettl, H., Gerloff, J., Heynig, H. (Eds.), Süsswasserflora von Mitteleuropa, Bd. 3. 1. Teil. Gustav Fischer Verlag, Stuttgart, pp. 1–530.
  13. ^ E. Negrisolo et al. (2004). Morphological convergence characterizes the evolution of Xanthophyceae (Heterokontophyta): evidence from nuclear SSU rDNA and plastidial rbcL genes. Molecular Phylogenetics and Evolution 33: 156–170.
  14. ^ a b Adl SM, Simpson AG, Farmer MA, et al. (2005). "The new higher level classification of eukaryotes with emphasis on the taxonomy of protists". The Journal of Eukaryotic Microbiology 52 (5): 399–451. doi:10.1111/j.1550-7408.2005.00053.x. PMID 16248873. 
  15. ^ Maistro S, Broady PA, Andreoli C, Negrisolo E (August 2009). "Phylogeny and taxonomy of Xanthophyceae (Stramenopiles, Chromalveolata)". Protist 160 (3): 412–26. doi:10.1016/j.protis.2009.02.002. PMID 19386545. 
  16. ^ Adl SM, Simpson AG, Lane CE, et al. (September 2012). "The revised classification of eukaryotes". The Journal of Eukaryotic Microbiology 59 (5): 429–93. doi:10.1111/j.1550-7408.2012.00644.x. PMC 3483872. PMID 23020233.