Thoreaceae Explained

Thoreales is an order of red algae belonging to the class Florideophyceae.^[1] The order consists only one family, Thoreaceae .^{[2] [3]} The family of Thoreaceae was circumscribed by Arthur Hill Hassall in A history of the British freshwater algae, including descriptions of the Desmideae and Diatomaceae in 1845.^[2]

The family was originally placed in the Nemaliales order before being transferred to the newly created Batrachospermales order,^{[4] [5] [6]} before being placed later in Thoreales order in 2002. After various species of the family were analysed for the sequences of the genes coding for the large subunit of RUBISCO (rbcL) and the small subunit of rRNA (18S rRNA).^{[1] [7]}

Description

The order is characterized by having freshwater species with multi-axial gametophytes, a uni-axial chantransia stage, and pit plugs with two cap layers, the outer one of which is usually plate-like.^[1] It has a multi-axial thalli.^[8] They have branched uniseriate filaments as long as 200cm (100inches) long and 0.5 mm in diameter. They have a colourless axis filament with dense photosynthetic lateral branches. They are normally reddish-brown, olive-green, blue-green to nearly black in colour.^[9]

Distribution

The family has cosmopolitan distribution.^[10] Species from the family are found in tropical and sub-tropical regions or in temperate warm waters. Thorea is found on several continents (including Australia,^[11] and South America), but Nemalionopsis has been only found in Asia and North America.^{[8] [12]}

Genera

As accepted by AlgaeBase;^[13]

• Nemalionopsis - 3 spp.
• Thorea - 13 spp.

Former genera;Polycoma and Thorella,^[13] Both accepted as synonyms of Thorea .^[14]

Notes and References

1. Müller . Kirsten M. . Sherwood . Alison R. . Pueschel . Curt M. . Gutell . Robin R. . Sheath . Robert G. . A proposal for a new red algal order, the Thoreales . Journal of Phycology . 16 August 2002 . 38 . 4 . 807–820 . 10.1046/j.1529-8817.2002.01055.x.
2. Hassall, A.H. 1845. A history of the British freshwater algae, including descriptions of the Desmideae and Diatomaceae. With upwards of one hundred plates, illustrating the various species. Vol. I. pp. [i]–viii, [i]–462, [i, err.]. London, Edinburgh, Paris & Leipzig: S. Highley, H. Baillière; Sunderland & Knox; J.B. Baillière; T.O. Weigel.
3. Kamiya, M., Lindstrom, S.C., Nakayama, T., Yokoyama, A., Lin, S.-M., Guiry, M.D., Gurgel, F.D.G., Huisman, J.M., Kitayama, T., Suzuki, M., Cho, T.O. & Frey, W. 2017. Rhodophyta. In: Syllabus of Plant Families, 13th ed. Part 2/2: Photoautotrophic eukaryotic Algae. (Frey, W. Eds), pp. [i]–xii, [1]–171. Stuttgart: Borntraeger Science Publishers. ISBN 978-3-443-01094-2.
4. Debashish Bhattacharya (Editor)
5. Pueschel . Curt M. . Cole . Kathleen M. . Rhodophycean Pit Plugs: An Ultrastructural Survey with Taxonomic Implications . American Journal of Botany . May–June 1982 . 69 . 5 . 703–720.
6. Pueschel . Curt M. . Sullivan . P. Gary . Titus . John E. . OCCURRENCE OF THE RED ALGA THOREA VIOLACEA (BATRACHOSPERMALES: THOREACEAE) IN THE HUDSON RIVER, NEW YORK STATE . Rhodora . Fall 1995 . 97 . 892 . 328–338.
7. Morgan L Vis, Orlando Necchi Jr and Orlando Necchi Júnior
8. Necchi Jr . Orlando . Taxonomy and distribution of Thorea (Thoreaceae, Rhodophyta) in Brazil . Algological Studies . January 1997 . 84 . 84–90 . Taxonomy and phylogeny of freshwater red algae.
9. Web site: Phycokey - Thorea . cfb.unh.edu . 13 December 2022.
10. Web site: Thoreaceae . www.gbif.org . 9 December 2022 . en.
11. P. M. McCarthy and Lyn Jessup
12. Sheath . Robert G. . Vis . Morgan L. . Cole . Kathleen M. . Distribution and systematics of the freshwater red algal family Thoreaceae in North America . European Journal of Phycology . 11 Aug 1993 . 28 . 4 . 231–241 . 10.1080/09670269300650341. free .
13. Web site: Taxonomy Browser :: AlgaeBase . www.algaebase.org . 13 December 2022.
14. Web site: WoRMS - World Register of Marine Species - Thoreaceae . www.marinespecies.org . 13 December 2022.