Florideophyceae

Last updated

Florideophyceae
Temporal range: Neoproterozoic–present [1]
Haeckel Florideae.jpg
"Florideae" from Ernst Haeckel's Kunstformen der Natur , 1904
Scientific classification OOjs UI icon edit-ltr.svg
(unranked): Archaeplastida
Division: Rhodophyta
Subdivision: Eurhodophytina
Class: Florideophyceae
Cronquist, 1960 [2]
Subgroups

See text.

Florideophyceae is a class of exclusively multicellular red algae. [3] [4] They were once thought to be the only algae to bear pit connections, [5] but these have since been found in the filamentous stage of the Bangiaceae. [6] They were also thought only to exhibit apical growth, but there are genera known to grow by intercalary growth. [6] Most, but not all, genera have three phases to the life cycle. [6]

Contents

Classification

A Laurencia red alga from Hawaii Laurencia.jpg
A Laurencia red alga from Hawaii

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

Subclass Hildenbrandiophycidae

Subclass Nemaliophycidae

Subclass Corallinophycidae

The subclass Corallinophycidae was introduced in 2007. [7]

Subclass Ahnfeltiophycidae

Subclass Rhodymeniophycidae

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. [1]

Related Research Articles

<span class="mw-page-title-main">Glaucophyte</span> Division of algae

The glaucophytes, also known as glaucocystophytes or glaucocystids, are a small group of unicellular algae found in freshwater and moist terrestrial environments, less common today than they were during the Proterozoic. The stated number of species in the group varies from about 14 to 26. Together with the red algae (Rhodophyta) and the green algae plus land plants, they form the Archaeplastida.

<span class="mw-page-title-main">Archaeplastida</span> Clade of eukaryotes containing land plants and some algae

The Archaeplastida are a major group of eukaryotes, comprising the photoautotrophic red algae (Rhodophyta), green algae, land plants, and the minor group glaucophytes. It also includes the non-photosynthetic lineage Rhodelphidia, a predatorial (eukaryotrophic) flagellate that is sister to the Rhodophyta, and probably the microscopic picozoans. The Archaeplastida have chloroplasts that are surrounded by two membranes, suggesting that they were acquired directly through a single endosymbiosis event by phagocytosis of a cyanobacterium. All other groups which have chloroplasts, besides the amoeboid genus Paulinella, have chloroplasts surrounded by three or four membranes, suggesting they were acquired secondarily from red or green algae. Unlike red and green algae, glaucophytes have never been involved in secondary endosymbiosis events.

<i>Paulinella</i> Genus of single-celled organisms

Paulinella is a genus of at least eleven species including both freshwater and marine amoeboids. Like many members of euglyphids it is covered by rows of siliceous scales, and use filose pseudopods to crawl over the substrate of the benthic zone.

<span class="mw-page-title-main">Ochrophyte</span> Phylum of algae

Ochrophytes, also known as heterokontophytes or stramenochromes, are a group of algae. They are the photosynthetic stramenopiles, a group of eukaryotes, organisms with a cell nucleus, characterized by the presence of two unequal flagella, one of which has tripartite hairs called mastigonemes. In particular, they are characterized by photosynthetic organelles or plastids enclosed by four membranes, with membrane-bound compartments called thylakoids organized in piles of three, chlorophyll a and c as their photosynthetic pigments, and additional pigments such as β-carotene and xanthophylls. Ochrophytes are one of the most diverse lineages of eukaryotes, containing ecologically important algae such as brown algae and diatoms. They are classified either as phylum Ochrophyta or Heterokontophyta, or as subphylum Ochrophytina within phylum Gyrista. Their plastids are of red algal origin.

<span class="mw-page-title-main">Red algae</span> Division of plant life

Red algae, or Rhodophyta, make up one of the oldest groups of eukaryotic algae. The Rhodophyta comprises one of the largest phyla of algae, containing over 7,000 recognized species amidst ongoing taxonomic revisions. The majority of species (6,793) are Florideophyceae, and mostly consist of multicellular, marine algae, including many notable seaweeds. Red algae are abundant in marine habitats. Approximately 5% of red algae species occur in freshwater environments, with greater concentrations in warmer areas. Except for two coastal cave dwelling species in the asexual class Cyanidiophyceae, no terrestrial species exist, which may be due to an evolutionary bottleneck in which the last common ancestor lost about 25% of its core genes and much of its evolutionary plasticity.

<i>Cyanophora paradoxa</i> Species of alga

Cyanophora paradoxa is a freshwater species of Glaucophyte that is used as a model organism. C. paradoxa has two cyanelles or chloroplasts where photosynthesis occurs. Cyanelles are unusual organelles in that they retain a rudimentary peptidoglycan wall. The cyanelle genome of C. paradoxa strain LB 555 was sequenced and published in 1995. The nuclear genome was also sequenced and published in 2012.

<span class="mw-page-title-main">Cyanidiophyceae</span> Class of algae

Cyanidiophyceae is a class of unicellular red algae within subdivision Cyanidiophytina, and contain a single plastid, one to three mitochondria, a nucleus, a vacuole, and floridean starch. Most are extremophiles inhabiting acid hot springs. The main photosynthetic pigment is C-phycocyanin. Reproduction is asexual by binary fission or formation of endospores. After the first massive gene loss in the common ancestor of all red algae, a second gene loss occurred in the ancestor of Cyanidiophyceae. Since then, some gene gains and minor gene losses have taken place independently in the Cyanidiaceae and Galdieriaceae, leading to genetic diversification between the two groups, with Galdieriaceae occupying more diverse and varied niches in extreme environments than Cyanidiaceae.

<span class="mw-page-title-main">Polykrikaceae</span> Family of single-celled organisms

The Polykrikaceae are a family of athecate dinoflagellates of the order Gymnodiniales. Members of the family are known as polykrikoids. The family contains two genera: Polykrikos and Pheopolykrikos.

<span class="mw-page-title-main">Hapalidiaceae</span> Family of algae

Hapalidiaceae is a family of red alga belonging to the order Corallinales.

Galdieria sulphuraria is an extremophilic unicellular species of red algae. It is the type species of the genus Galdieria. It is known for its broad metabolic capacities, including photosynthesis and heterotrophic growth on over 50 different extracellular carbon sources. The members of the class Cyanidiophyceae are among the most acidophilic known photosynthetic organisms, and the growth conditions of G. sulphuraria – pH between 0 and 4, and temperatures up to 56 °C – are among the most extreme known for eukaryotes. Analysis of its genome suggests that its thermoacidophilic adaptations derive from horizontal gene transfer from archaea and bacteria, another rarity among eukaryotes.

<span class="mw-page-title-main">Christine Maggs</span> British phycologist

Christine Adair Maggs is a British phycologist. Formerly Executive Dean of the Faculty of Science & Technology at Bournemouth University, she was the first Chief Scientist of the Joint Nature Conservation Committee, retiring in 2022. She is now an independent non-executive Director of Ocean Harvest Technology https://oceanharvesttechnology.com/corporate-governance/board-of-directors/

<span class="mw-page-title-main">Batrachospermaceae</span> Family of algae

Batrachospermaceae is a family of fresh water red algae (Rhodophyta). Genera within the Batrachospermaceae generally have a "Lemanea-type" life history with carpospores germinating to produce chantransia. Sporophyte phase with meiosis occurs in an apical cell to produce the gametophyte stage. Pit connections have two pit plug cap layers with the other layer enlarged. This family of freshwater red algae is uniaxial, meaning each filament with a single apical cell. The genera included within Batrachospermaceae are listed in the table below.

<span class="mw-page-title-main">Cyanidiophytina</span> Group of algae

Cyanidiophytina is a subdivision of red algae.

Galdieria is a genus of red algae belonging to the order Galdieriales; family Galdieriaceae. It was created by an Italian botanist Aldo Merola in 1981 for the identification from the species of Cyanidium.

Crustaphytum is a genus of red alga first discovered in Taoyuan algal reefs by Taiwanese scientists. The epithet “crusta” refers to crustose thallus and “phytum” refers to plant. Belonging to the family Hapalidiaceae in the order Hapalidiales, Crustaphytum is one kind of crustose coralline algae.

<span class="mw-page-title-main">Naccariaceae</span> Family of algae

Naccariaceae is a family of red algae in the order Bonnemaisoniales, with 3 monotypic genera that are found in both the Pacific and Atlantic Oceans.

<span class="mw-page-title-main">Liagoraceae</span> Family of algae

Liagoraceae is a family of red algae (Rhodophyta) in the order Nemaliales. The type genus is LiagoraJ.V.Lamouroux.

<span class="mw-page-title-main">Thoreaceae</span> Order of algae

Thoreales is an order of red algae belonging to the class Florideophyceae. The order consists only one family, ThoreaceaeHassall, 1845. 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.

<span class="mw-page-title-main">Halymeniales</span> Order of algae

Halymeniales is an order of red algae belonging to the class Florideophyceae and the subclass Rhodymeniophycidae.

<span class="mw-page-title-main">Peyssonneliales</span> Order of algae

Peyssonneliales is a monotypic order of red algae belonging to the class Florideophyceae and the subclass Rhodymeniophycidae. It contains only 1 known family, PeyssonneliaceaeDenizot, M., 1968.

References

  1. 1 2 Yang, Eun Chan; Boo, Sung Min; Bhattacharya, Debashish; Saunders, Gary W.; Knoll, Andrew H.; Fredericq, Suzanne; Graf, Louis; Yoon, Hwan Su (2016). "Divergence time estimates and the evolution of major lineages in the florideophyte red algae". Scientific Reports. 6: 21361. Bibcode:2016NatSR...621361Y. doi:10.1038/srep21361. PMC   4759575 . PMID   26892537.
  2. Cronquist, A. (1960). "The divisions and classes of plants". The Botanical Review. 26 (4): 425–482. Bibcode:1960BotRv..26..425C. doi:10.1007/BF02940572. S2CID   43144314.
  3. Yoon, Hwan Su; Muller, Kirsten M.; Sheath, Robert G.; Ott, Franklyn D.; Bhattacharya, Debashish (April 2006). "Defining the Major Lineages of Red Algae (Rhodophyta)1". Journal of Phycology. 42 (2): 482–492. Bibcode:2006JPcgy..42..482Y. doi:10.1111/j.1529-8817.2006.00210.x. ISSN   0022-3646. S2CID   27377549.
  4. Petroll, Romy; Schreiber, Mona; Finke, Hermann; Cock, J. Mark; Gould, Sven B.; Rensing, Stefan A. (9 July 2021). "Signatures of Transcription Factor Evolution and the Secondary Gain of Red Algae Complexity". Genes. 12 (7): 1055. doi: 10.3390/genes12071055 . PMC   8304369 . PMID   34356071.
  5. Dawes, C. J.; Scott, F. M.; Bowler, E. (1961). "A Light- and Electron-Microscopic Survey of Algal Cell Walls. I. Phaeophyta and Rhodophyta". American Journal of Botany. 48 (10): 925–934. doi:10.2307/2439535. JSTOR   2439535.
  6. 1 2 3 Lee, R.E. (2008). Phycology, 4th edition . Cambridge University Press. ISBN   978-0-521-63883-8.
  7. Le Gall L, Saunders GW (June 2007). "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. Bibcode:2007MolPE..43.1118L. doi:10.1016/j.ympev.2006.11.012. PMID   17197199.