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Chlorophyta

From Wikipedia, the free encyclopedia
This article is about a group of green algae. For the genus with the common name 'spider plant', see Chlorophytum.

Chlorophyta
Chlorophytes (A–F, H–L and O)
Scientific classification Edit this classification
Domain: Eukaryota
Clade: Diaphoretickes
(unranked): Archaeplastida
(unranked): Viridiplantae
Division: Chlorophyta
Reichenbach, 1828, emend. Pascher, 1914, emend. Lewis & McCourt, 2004[1][2][3]
Classes[4]
Diversity
7,934 species
(6,851 extant, 1,083 fossil)[4]
Synonyms
  • Chlorophycophyta Papenfuss 1946[5]
  • Chlorophycota
  • Chlorophytina
  • Chlorophyllophyceae
  • Isokontae
  • Stephanokontae
Green algae on coastal rocks at Shihtiping in Taiwan

Chlorophyta is a taxon of green algae informally called chlorophytes.[6]

Systematics

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Taxonomy

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The name Chlorophyta was historically attributed to a paraphyletic group of all green algae, i.e., all organisms belonging to the Viridiplantae with the exception of land plants (Embryophyta).[7] In modern classifications, Chlorophyta is only one of the many clades of green algae, sister to the Streptophyta clade from which land plants evolved.[8][9] In this latter sense, the Chlorophyta includes only about 7,900 species.[4] About 90% of all known species live in freshwater.[10] Like other green algae and land plants, chlorophytes contain chlorophylls a and b, and store food as starch in their plastids.[7]

With the exception of the three classes Ulvophyceae, Trebouxiophyceae and Chlorophyceae in the UTC clade, which show various degrees of multicellularity, all the Chlorophyta lineages are unicellular.[11] Some members of the group form symbiotic relationships with protozoa, sponges, and cnidarians. Others form symbiotic relationships with fungi to form lichens, but the majority of species are free-living. Some conduct sexual reproduction, which is oogamous or isogamous. All members of the clade have motile flagellated swimming cells.[12] Monostroma kuroshiense, an edible green alga cultivated worldwide and most expensive among green algae, belongs to this group.

Ecology

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Most species of Chlorophyta are aquatic, prevalent in both marine and freshwater environments. However, some species have adapted to a wide range of terrestrial environments. For example, Chlamydomonas nivalis lives on summer alpine snowfields, and Trentepohlia species, live attached to rocks or woody parts of trees.[13][14] Several species have adapted to specialised and extreme environments, such as deserts, arctic environments, hypersaline habitats, marine deep waters, deep-sea hydrothermal vents and habitats that experiences extreme changes in temperature, light and salinity.[15][16][17][18] Some groups, such as the Trentepohliales are exclusively found on land.[19] Several species of Chlorophyta live in symbiosis with a diverse range of eukaryotes, including fungi (to form lichens), ciliates, forams, cnidarians and molluscs.[14] Some species of Chlorophyta are heterotrophic, either free-living or parasitic.[20][21] Others are mixotrophic bacterivores through phagocytosis.[22] Two common species of the heterotrophic green alga Prototheca are pathogenic and can cause the disease protothecosis in humans and animals.[23]

Classifications

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"Siphoneae" from Ernst Haeckel's Kunstformen der Natur, 1904
Further information: Wikispecies:Chlorophyta

Characteristics used for the classification of Chlorophyta are: type of zoid, mitosis (karyokinesis), cytokinesis, organization level, life cycle, type of gametes, cell wall polysaccharides[24] and more recently genetic data.

Phylogeny

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Leliaert et al. 2012 proposed the following phylogeny. He marked the "prasinophytes" as paraphyletic, with the remaining Chlorophyta groups as "core chlorophytes". He described all Streptophyta except the land plants as paraphyletic "charophytes".[14]

"Hypothetical ancestral
green flagellate"

A 2020 paper places the "Prasinodermophyta" (i.e. Prasinodermophyceae + Palmophyllophyceae) as the basal Viridiplantae clade.[25]

Viridiplantae/
Green Algae/
Prasinophyta s.l.

Leliaert et al. 2012

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Simplified phylogeny of the Chlorophyta, according to Leliaert et al. 2012.[14] Note that many algae previously classified in Chlorophyta are placed here in Streptophyta.

Pombert et al. 2005

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A possible classification when Chlorophyta refers to one of the two clades of the Viridiplantae is shown below.[26]

Lewis & McCourt 2004

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Hoek, Mann and Jahns 1995

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Classification of the Chlorophyta, treated as all green algae, according to Hoek, Mann and Jahns 1995.[7]

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

Bold and Wynne 1985

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Classification of the Chlorophyta and Charophyta according to Bold and Wynne 1985.[27]

Mattox & Stewart 1984

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Classification of the Chlorophyta according to Mattox & Stewart 1984:[28]

Fott 1971

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Classification of the Chlorophyta according to Fott 1971.[29]

Round 1971

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Classification of the Chlorophyta and related algae according to Round 1971.[30]

Smith 1938

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Classification of the Chlorophyta according to Smith 1938:

Fossil record

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In February 2020, the fossilized remains of green algae, named Proterocladus antiquus were discovered in the northern province of Liaoning, China. At around a billion years old, it is believed to be one of the oldest examples of a multicellular chlorophyte.[31]

References

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Citations

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  1. ^ Reichenbach 1828, p. 23.
  2. ^ Pascher 1914.
  3. ^ Adl et al. 2019, p. 36.
  4. ^ a b c Guiry 2024.
  5. ^ Papenfuss 1955.
  6. ^ Rockwell et al. 2017.
  7. ^ a b c van den Hoek, Mann & Jahns 1995.
  8. ^ Lewis & McCourt 2004.
  9. ^ Becker & Marin 2009.
  10. ^ Lee 2018.
  11. ^ Umen 2014.
  12. ^ Kapraun 2007.
  13. ^ Graham et al. 2022.
  14. ^ a b c d Leliaert et al. 2012.
  15. ^ Lewis & Lewis 2005.
  16. ^ De Wever et al. 2009.
  17. ^ Leliaert, Verbruggen & Zechman 2011.
  18. ^ Foflonker et al. 2016.
  19. ^ López-Bautista, Rindi & Guiry 2006.
  20. ^ Joubert & Rijkenberg 1971.
  21. ^ Nedelcu 2001.
  22. ^ Anderson, Charvet & Hansen 2018.
  23. ^ Tartar et al. 2002.
  24. ^ Lobban & Wynne 1981, p. 88.
  25. ^ Li et al. 2020.
  26. ^ Pombert et al. 2005.
  27. ^ Bold & Wynne 1985.
  28. ^ Mattox & Stewart 1984.
  29. ^ van den Hoek, Mann & Jahns 1995, p. 483.
  30. ^ Round 1971.
  31. ^ Tang et al. 2020.

Cited literature

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Further reading

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Wikispecies has information related to Chlorophyta.
Wikimedia Commons has media related to Chlorophyta.
  • Burrows EM (1991). Seaweeds of the British Isles. Vol. 2 (Chlorophyta). London: Natural History Museum. ISBN 978-0-565-00981-6.
  • Pickett-Heaps JD (1975). Green Algae. Structure, Reproduction and Evolution in Selected Genera. Stamford, CT: Sinauer Assoc. p. 606.
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