Chlorophyta

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Chlorophyta
Haeckel Siphoneae.jpg
"Siphoneae" from Ernst Haeckel's Kunstformen der Natur, 1904
Scientific classification e
Kingdom: Viridiplantae
Division: Chlorophyta
Reichenbach, 1834; Pascher[1][2]
Classes[3]
Synonyms
  • Chlorophycophyta
  • Chlorophyllophyceae
  • Isokontae
  • Stephanokontae[4]
Green algae on coastal rocks at Shihtiping in Taiwan

Chlorophyta is a division of green algae, informally called chlorophytes. The name is used in two very different senses, so care is needed to determine the use by a particular author. In older classification systems, it refers to a highly paraphyletic group of all the green algae within the green plants (Viridiplantae) and thus includes about 7,000 species[5][6] of mostly aquatic photosynthetic eukaryotic organisms. In newer classifications, it refers to one of the two clades making up the Viridiplantae, which are the chlorophytes and the streptophytes. The clade Streptophyta consists of two divisions, the Charophyta and the Embryophyta.[7][8] In this sense the Chlorophyta includes only about 4,300 species.[3] Like the land plants (bryophytes and tracheophytes), green algae contain chlorophyll a and chlorophyll b and store food as starch[5] in their plastids.

The division contains both unicellular and multicellular species. While most species live in freshwater habitats and a large number in marine habitats, other species are adapted to a wide range of environments. Watermelon snow, or Chlamydomonas nivalis, of the class Chlorophyceae, lives on summer alpine snowfields. Others live attached to rocks or woody parts of trees. Some lichens are symbiotic relationships between fungi and green algae.

Members of the Chlorophyta also form symbiotic relationships with protozoa, sponges, and cnidarians. All are flagellated,[9] and these have an advantage of motility. Some conduct sexual reproduction, which is oogamous or isogamous.


Ecology[edit]

Species of Chlorophyta (treated as what is now considered one of the two clades of Viridiplantae) are common inhabitants of marine, freshwater and terrestrial environments.[10][11] Several species have adapted to specialised and extreme environments, such as deserts, arctic environments, hypersaline habitats, marine deep waters and deep-sea hydrothermal vents. [12][13][14] Some groups, such as the Trentepohliales are exclusively found on land.[15] Several species of Chlorophyta live in symbiosis with a diverse range of eukaryotes, including fungi (to form lichens), ciliates, forams, cnidarians and molluscs. [11] Some species of Chlorophyta are heterotrophic, either free-living or parasitic.[16][17] Two common species of the heterotrophic green alga Prototheca are pathogenic and can cause the disease protothecosis in humans and animals.[18]

Classifications[edit]

Characteristics like type of zoid, mitosis (karyokynesis), cytokinesis, organization level, life cycle, type of gametes, cell wall polysaccharides[19] and more recently genetic data are used for the classification of Chlorophyta.

Leliaert et al. 2012[edit]

Simplified phylogeny of the Chlorophyta, according to Leliaert et al. 2012.[11] Note that many algae before classified in Chlorophyta are replaced here in Streptophyta.

Pombert et al. 2005[edit]

A possible classification when Chlorophyta refers to one of the two clades of the Viridiplantae is shown below.[20]

Lewis & McCourt 2004[edit]

Hoek, Mann and Jahns 1995[edit]

Classification of the Chlorophyta, treated as all green algae, according to Hoek, Mann and Jahns 1995.[5]

In a note added in proof, an alternative classification is presented for the algae of the class Chlorophyceae:

Bold and Wynne 1985[edit]

Classification of the Chlorophyta (treated as what has since been considered one of the two clades of the Viridiplantae) according to Bold and Wynne 1985.[21]

Fott 1971[edit]

Classification of the Chlorophyta according to Fott 1971.[22]

Round 1971[edit]

Classification of the Chlorophyta and related algae according to Round 1971.[23]

Smith 1938[edit]

Classification of the Chlorophyta according to Smith 1938:

References[edit]

  1. ^ Pascher A (1914). "Über Flagellaten und Algen". Berichte der deutsche botanischen Gesellschaft 32: 136–160. 
  2. ^ Adl SM, Simpson AGB, Farmer MA, Andersen RA, Anderson OR, Barta JR, Bowser SS, Brugerolle G, Fensome RA, Fredericq S, James TY, Karpov S, Kugrens P, Krug J, Lane CE, Lewis LA, Lodge J, Lynn DH, Mann DG, McCourt RM, Mendoza L, Moestrup Ø, Mozley-Standridge SE, Nerad TA, Shearer CA, Smirnov AV, Speigel FW, Taylor MFJR (2005). "The new higher level classification of eukaryotes with emphasis on the taxonomy of protists". Journal of Eukaryotic Microbiology 52 (5): 399–451. doi:10.1111/j.1550-7408.2005.00053.x. PMID 16248873. 
  3. ^ a b Guiry, M.D. & Guiry, G.M. (2011). "AlgaeBase : Chlorophyta". World-wide electronic publication, National University of Ireland, Galway. Retrieved 2011-07-26 
  4. ^ http://archive.org/stream/centuryofprogres00cali#page/126/mode/1up
  5. ^ a b c Hoek, C. van den, Mann, D.G. and Jahns, H.M. 1995. Algae An Introduction to Phycology. Cambridge University Press, Cambridge. ISBN 0-521-30419-9
  6. ^ "Major Algae Phyla - Table - MSN Encarta". Archived from the original on 2009-10-31. 
  7. ^ Lewis, Louise A. & McCourt, R.M. (2004). "Green algae and the origin of land plants". Am. J. Bot. 91 (10): 1535–1556. doi:10.3732/ajb.91.10.1535. PMID 21652308 
  8. ^ Becker, B. & Marin, B. (2009). "Streptophyte algae and the origin of embryophytes". Annals of Botany 103 (7): 999–1004. doi:10.1093/aob/mcp044. PMC 2707909. PMID 19273476 
  9. ^ Kapraun DF (April 2007). "Nuclear DNA Content Estimates in Green Algal Lineages: Chlorophyta and Streptophyta". Ann. Bot. 99 (4): 677–701. doi:10.1093/aob/mcl294. PMC 2802934. PMID 17272304. 
  10. ^ Graham LE, Graham JM, Wilcox LW (2009) Algae. 2nd Edition. Benjamin Cummings (Pearson), San Francisco, CA
  11. ^ a b c Leliaert, F., Smith, D.R., Moreau, H., Herron, M.D., Verbruggen, H., Delwiche, C.F. & De Clerck, O. (2012). "Phylogeny and molecular evolution of the green algae" (PDF). Critical Reviews in Plant Sciences 31: 1–46. doi:10.1080/07352689.2011.615705. 
  12. ^ Lewis, Louise; Lewis, Paul (2005). "Unearthing the Molecular Phylodiversity of Desert Soil Green Algae (Chlorophyta)". Systematic Biology 54 (6): 936–947. doi:10.1080/10635150500354852. ISSN 1063-5157. 
  13. ^ De Wever, A.; Leliaert, F.; Verleyen, E.; Vanormelingen, P.; Van der Gucht, K.; Hodgson, D. A.; Sabbe, K.; Vyverman, W. (2009). "Hidden levels of phylodiversity in Antarctic green algae: further evidence for the existence of glacial refugia". Proceedings of the Royal Society B: Biological Sciences 276 (1673): 3591–3599. doi:10.1098/rspb.2009.0994. ISSN 0962-8452. 
  14. ^ Leliaert, Frederik; Verbruggen, Heroen; Zechman, Frederick W. (2011). "Into the deep: New discoveries at the base of the green plant phylogeny". BioEssays 33 (9): 683–692. doi:10.1002/bies.201100035. ISSN 0265-9247. PMID 21744372. 
  15. ^ Lopez-Bautista, J. M. (2006). "Molecular systematics of the subaerial green algal order Trentepohliales: an assessment based on morphological and molecular data". Int J Syst Evol Microbiol 56 (7): 1709–1715. doi:10.1099/ijs.0.63990-0. ISSN 1466-5026. 
  16. ^ Joubert, J. J. & F. H. J. Rijkenberg (1971). "Parasitic green algae". Annu. Rev. Phytopathol. 9: 45–64. doi:10.1146/annurev.py.09.090171.000401. 
  17. ^ Nedelcu, Aurora M. (2001). "Complex Patterns of Plastid 16S rRNA Gene Evolution in Nonphotosynthetic Green Algae". Journal of Molecular Evolution 53 (6): 670–679. doi:10.1007/s002390010254. ISSN 0022-2844. 
  18. ^ Tartar A, Boucias DG, Adams BJ, Becnel JJ (2002). "Phylogenetic analysis identifies the invertebrate pathogen Helicosporidium sp as a green alga (Chlorophyta)". Int J Syst Evol Microbiol 52 (Pt 1): 273–9. PMID 11837312. 
  19. ^ Lobban, Christopher S.; Wynne, Michael James, eds. (1981). The Biology of Seaweeds. Botanical Monograph Series 17. University of California Press, p. 88.
  20. ^ Jean-Francxois Pombert et al 2005, The Chloroplast Genome Sequence of the Green Alga Pseudendoclonium akinetum (Ulvophyceae) Reveals Unusual Structural Features and New Insights into the Branching Order of Chlorophyte Lineages Mol. Biol. Evol. 22(9) 1903–1918. doi:10.1093/molbev/msi182
  21. ^ Bold, H.C. & Wynne, M.J. (1985). Introduction to the algae : structure and reproduction (2nd ed.). Englewood Cliffs, N.J.: Prentice-Hall. ISBN 978-0-13-477746-7 
  22. ^ Hoek, C. et al. (1995), p. 483.
  23. ^ Round, F.E. 1971. The taxonomy of the Chlorophyta, 2. Brit. phycol. J., 6(2): 235-264.

Further reading[edit]

  • Burrows, E.M. 1991. Seaweeds of the British Isles. Volume 2 Chlorophyta. Natural History Museum, London. ISBN 0-565-00981-8
  • Lewis, L. A. & McCourt, R. M. (2004). "Green algae and the origin of land plants". American Journal of Botany 91 (10): 1535–1556. doi:10.3732/ajb.91.10.1535. PMID 21652308. 
  • Pickett-Heaps, J.D. (1975). Green Algae. Structure, Reproduction and Evolution in Selected Genera. Sinauer Assoc., Stamford, CT; 606 pages.