Florideophyceae Explained

Florideophyceae is a class of exclusively multicellular red algae.^{[1] [2]} They were once thought to be the only algae to bear pit connections,^[3] but these have since been found in the filamentous stage of the Bangiaceae.^[4] They were also thought only to exhibit apical growth, but there are genera known to grow by intercalary growth. Most, but not all, genera have three phases to the life cycle. In the subclass Nemaliophycidae there are three orders, Balbianiales, Batrachospermales, and Thoreales, which lives exclusively in freshwater.^[5]

Classification

There are various classification schemes; see red algae. One option is to use the following:

Subclass Hildenbrandiophycidae

• Hildenbrandiales

Subclass Nemaliophycidae

• Acrochaetiales
• Balbianiales
• Balliales
• Batrachospermales
• Colaconematales
• Nemaliales
• Palmariales
• Entwisleiales
• Thoreales

Subclass Corallinophycidae

• Corallinales
• Corallinapetrales
• Rhodogorgonales
• Sporolithales

The subclass Corallinophycidae was introduced in 2007.^[6]

Subclass Ahnfeltiophycidae

• Ahnfeltiales
• Pihiellales

Subclass Rhodymeniophycidae

• Bonnemaisoniales
• Ceramiales
• Gelidiales
• Gigartinales
• Gracilariales
• Halymeniales
• Nemastomatales
• Peyssonneliales
• Plocamiales
• Rhodymeniales
• Acrosymphytales
• Atractophorales
• Catenellopsidales
• Sebdeniales

According to molecular clock analysis, Florideophyceae diverged from other red algae about 943 (817–1,049) million years ago. It split into Hildenbrandiophycidae ca. 781 (681–879) mya, Nemaliophycidae ca. 661 (597–736) mya and Corallinophycidae ca. 579 (543–617) mya, and ca. 508 (442–580) mya the split between Ahnfeltiophycidae and Rhodymeniophycidae occurred.

External links

• Tree of Life: Florideophyceae

Notes and References

1. Yoon. Hwan Su. Muller. Kirsten M.. Sheath. Robert G.. Ott. Franklyn D.. Bhattacharya. Debashish. Defining the Major Lineages of Red Algae (Rhodophyta)1 . April 2006. Journal of Phycology. en. 42. 2. 482–492. 10.1111/j.1529-8817.2006.00210.x. 2006JPcgy..42..482Y . 27377549 . 0022-3646.
2. Petroll . Romy . Schreiber . Mona . Finke . Hermann . Cock . J. Mark . Gould . Sven B. . Rensing . Stefan A. . 2021-07-09 . Signatures of Transcription Factor Evolution and the Secondary Gain of Red Algae Complexity . Genes . 12 . 7 . 1055 . 10.3390/genes12071055 . free . 8304369 . 34356071.
3. 10.2307/2439535 . Dawes . C. J. . Scott . F. M. . Bowler . E. . A Light- and Electron-Microscopic Survey of Algal Cell Walls. I. Phaeophyta and Rhodophyta . American Journal of Botany . 48 . 10 . 925–934 . 1961. 2439535 .
4. Book: Lee, R.E.. Phycology, 4th edition. 2008. 978-0-521-63883-8. Cambridge University Press. registration.
5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7799738/ Complete mitochondrial genomes of six species of the freshwater red algal order Batrachospermales (Rhodophyta)
6. Le Gall L, Saunders GW . A nuclear phylogeny of the Florideophyceae (Rhodophyta) inferred from combined EF2, small subunit and large subunit ribosomal DNA: establishing the new red algal subclass Corallinophycidae . Mol. Phylogenet. Evol. . 43 . 3 . 1118–30 . June 2007 . 17197199 . 10.1016/j.ympev.2006.11.012 . 2007MolPE..43.1118L .