Ulvophyceae Explained

The Ulvophyceae or ulvophytes are a class of green algae, distinguished mainly on the basis of ultrastructural morphology, life cycle and molecular phylogenetic data.^[1] The sea lettuce, Ulva, belongs here. Other well-known members include Caulerpa, Codium, Acetabularia, Cladophora, Trentepohlia and Monostroma.

The Ulvophytes are diverse in their morphology and their habitat. Most are seaweeds such as those listed above. Others, such as Rhizoclonium, Pithophora and some species of Cladophora live in fresh water^[2] and in some areas are considered weeds.^[3]

Evolution

The origin and early diversification of the Ulvophyceae likely took place in the late Neoproterozoic,^{[4] [5]} though may have taken place earlier, in the Mesoproterozoic.^[6] Although most contemporary ulvophytes are marine macroalgae (seaweeds), ancestral ulvophytes may have been freshwater, unicellular green algae. Molecular phylogenetic evidence suggests that macroscopic growth was achieved independently in the various major lineages of Ulvophyceae (Ulvales-Ulotrichales, Trentepohliales, Cladophorales, Bryopsidales and Dasycladales). Fossils are rare but there are some good candidates in a mid-Ordovician lagerstatten.

Current hypothesis on relationships among the main clades of Ulvophyceae^{[7] [8]} are shown below.

See also

• List of Ulvophyceae genera

Notes and References

1. Book: Graham LE, Graham JM, Wilcox LW . 2009 . Algae . 2nd . Benjamin Cummings (Pearson) . San Francisco, CA .
2. Book: Evolution of Primary Producers in the Sea. O'Kelly CJ . Academic Press. 2007. 9780123705181. 297. The Origin and Early Evolution of Green Plants. 10.1016/B978-012370518-1/50014-X.
3. Web site: Terms for Weeds Your Lake Bottom Blanket Prevents. https://web.archive.org/web/20200926075501/https://www.lakemat.com/terms-for-weeds-your-lake-bottom-blanket-prevents/ . 26 September 2020 . Lakemat . 2 November 2019.
4. Verbruggen H, Ashworth M, LoDuca ST, Vlaeminck C, Cocquyt E, Sauvage T, Zechman FW, Littler DS, Littler MM, Leliaert F, De Clerck O . A multi-locus time-calibrated phylogeny of the siphonous green algae . Molecular Phylogenetics and Evolution . 50 . 3 . 642–653 . March 2009 . 19141323 . 10.1016/j.ympev.2008.12.018 . Diane S. Littler .
5. Cocquyt E, Verbruggen H, Leliaert F, De Clerck O . Evolution and cytological diversification of the green seaweeds (Ulvophyceae) . Molecular Biology and Evolution . 27 . 9 . 2052–2061 . September 2010 . 20368268 . 10.1093/molbev/msq091 . free .
6. Hou Z, Ma X, Shi X, Li X, Yang L, Xiao S, De Clerck O, Leliaert F, Zhong B . Phylotranscriptomic insights into a Mesoproterozoic-Neoproterozoic origin and early radiation of green seaweeds (Ulvophyceae) . Nature Communications . 13 . 1 . 1610 . March 2022 . 35318329 . 8941102 . 10.1038/s41467-022-29282-9 .
7. Leliaert F, Smith DR, Moreau H, Herron MD, Verbruggen H, Delwiche CF, De Clerck O . 2012 . Phylogeny and molecular evolution of the green algae . 10.1080/07352689.2011.615705 . Critical Reviews in Plant Sciences . 31 . 1–46 . 17603352 .
8. Škaloud P, Kalina T, Nemjová K, De Clerck O, Leliaert F . Morphology and Phylogenetic Position of the Freshwater Green Microalgae Chlorochytrium (Chlorophyceae) and Scotinosphaera (Scotinosphaerales, ord. nov., Ulvophyceae) . Journal of Phycology . 49 . 1 . 115–129 . February 2013 . 27008394 . 10.1111/jpy.12021 . 7359581 .