NationMaster - Encyclopedia: Red algae

The red algae (Rhodophyta, IPA: /ˌroʊdəˈfaɪtə, roʊˈdɒfɨtə/, from Greek: ῥόδον (rhodon) = rose + φυτόν (phyton) = plant, thus red plant) are a large group, about 5,000–6,000 species ^[1] of mostly multicellular, marine algae, including many notable seaweeds. Other references indicate 10,000 species. ^[2] Most of the coralline algae, which secrete calcium carbonate and play a major role in building coral reefs, belong here. Red algae such as dulse (Palmaria palmata) and nori are a traditional part of European and Asian cuisine and are used to make other products like agar, carrageenans and other food additives. ^[3] ImageMetadata File history File links Download high resolution version (900x722, 561 KB) Close-up of a red alga (Laurencia), a marine seaweed from Hawaii. ... For other uses, see Scientific classification (disambiguation). ... Kingdoms Eukaryotes are organisms with complex cells, in which the genetic material is organized into membrane-bound nuclei. ... The Archaeplastida are a major line of eukaryotes, comprising the land plants, green and red algae, and a small group called the glaucophytes. ... Richard Wettstein (June 30, 1863 - August 10, 1931) was an Austrian botanist. ... Orders See text. ... Orders Bangiales Cyanidiales Erythropeltidales Porphyridiales Rhodochaetales Stylonematales Bangiophyceae is a class of Red algae. ... Multicellular organisms are those organisms containing more than one cell, and having differentiated cells that perform specialized functions. ... Animated map exhibiting the worlds oceanic waters. ... Algae have conventionally been regarded as simple plants within the study of botany. ... Ascophyllum nodosum exposed to the sun in Nova Scotia, Canada Dead Mans Fingers (Codium fragile) off Massachusetts coast For the band, see; Seaweed (band) For the rock musician, see; Seaweed (musician) Seaweeds are any of a large number of marine benthic algae. ... Genera 39 genera Coralline algae are red algae in the Family Corallinaceae characteriuzed by a thallus covered with calcareous deposits. ... Calcium carbonate is a chemical compound, with the chemical formula CaCO3. ... Some of the biodiversity of a coral reef, in this case the Great Barrier Reef, Australia. ... Binomial name Palmaria palmata (Linnaeus) Kuntze, 1891 Dulse (Palmaria palmata (L.) Kuntze), also called dillisk, dilsk, dulse or creathnach, is a red alga (Rhodophyta) that grows on the northern coasts of the Atlantic and Pacific oceans. ... For other uses, see Nori (disambiguation). ... For other uses, see Europe (disambiguation). ... For other uses, see Asia (disambiguation). ... This does not adequately cite its references or sources. ... Carrageenans or carrageenins (pronounced ) are a family of linear sulphated polysaccharides extracted from red seaweeds. ... Food additives are substances added to food to preserve it, or to improve its flavour and appearance. ...

Fossil record

The oldest fossil identified as a red alga is also the oldest fossil eukaryote that belongs to a specific modern taxon. Bangiomorpha pubescens, a multicellular fossil from arctic Canada, strongly resembles the modern red alga Bangia despite occurring in rocks dating to 1200 million years ago. ^[4] Kingdoms Animalia - Animals Fungi Plantae - Plants Chromalveolata Protista Alternative phylogeny Unikonta Opisthokonta Metazoa Choanozoa Eumycota Amoebozoa Bikonta Apusozoa Cabozoa Rhizaria Excavata Corticata Archaeplastida Chromalveolata Animals, plants, fungi, and protists are eukaryotes (IPA: ), organisms whose cells are organized into complex structures by internal membranes and a cytoskeleton. ... A taxon (plural taxa), or taxonomic unit, is a grouping of organisms (named or unnamed). ...

Red algae are important builders of limestone reefs. The earliest such coralline algae, the solenopores, are known from the Cambrian Period. Other algae of different origins filled a similar role in the late Paleozoic, and in more recent reefs. For other uses, see Cambrian (disambiguation). ... The Paleozoic Era (from the Greek palaio, old and zoion, animals, meaning ancient life) is the earliest of three geologic eras of the Phanerozoic eon. ...

Taxonomy

The diverse eukaryotes that constitute the red algae have been the focus of numerous recent molecular surveys and remain a rich source of undescribed and little known species for the traditional taxonomist. Molecular studies place the red algae in the Archaeplastida (Plantae sensu lato); however, supraordinal classification has been largely confined to debate on subclass vs. class level status for the two recognized subgroups, one of which is widely acknowledged as paraphyletic. This narrow focus has generally masked the extent to which red algal classification needs modification. Kingdoms Animalia - Animals Fungi Plantae - Plants Chromalveolata Protista Alternative phylogeny Unikonta Opisthokonta Metazoa Choanozoa Eumycota Amoebozoa Bikonta Apusozoa Cabozoa Rhizaria Excavata Corticata Archaeplastida Chromalveolata Animals, plants, fungi, and protists are eukaryotes (IPA: ), organisms whose cells are organized into complex structures by internal membranes and a cytoskeleton. ... Taxonomy (from Greek ταξινομία from the words taxis = order and nomos = law) may refer to either a hierarchical classification of things, or the principles underlying the classification. ... The Archaeplastida are a major line of eukaryotes, comprising the land plants, green and red algae, and a small group called the glaucophytes. ... Sensu is a Latin term meaning in the sense of. It is used in taxonomy to specify which circumscription of a given taxon is meant, where more than one circumscription has been defined. ...

Below are two valid published taxonomies of the red algae, although neither necessarily has to be used, as the taxonomy of the algae is still in a state of flux. Note also that there is continued scientific debate as to whether the Rhodophyta should be included in the Kingdom Protista or the Kingdom Plantae. These two classification systems, which place the red algae in the plant kingdom, are shown in the table below.

For other uses, see Plant (disambiguation). ... Red algae Classes Florideophyceae Bangiophyceae Cyanidiophyceae The red algae are a large group of mostly multicellular, marine algae, including many notable seaweeds. ... Orders Bangiales Cyanidiales Erythropeltidales Porphyridiales Rhodochaetales Stylonematales Bangiophyceae is a class of Red algae. ... Orders See text. ... For other uses, see Plant (disambiguation). ... Red algae Classes Florideophyceae Bangiophyceae Cyanidiophyceae The red algae are a large group of mostly multicellular, marine algae, including many notable seaweeds. ... Orders Bangiales Cyanidiales Erythropeltidales Porphyridiales Rhodochaetales Stylonematales Bangiophyceae is a class of Red algae. ... Orders See text. ...

Species

There are around 6,500 to 10,000 known species, ^[2]^[3] nearly all of which are marine, with about 200 that only live in fresh water. However estimates of the number of real species vary by 100%. ^[2] Some examples are: For the village on the Isle of Wight, see Freshwater, Isle of Wight. ...

There are very few or no other articles that link to this one. ... Species G. calcicola And others Gelidiella is a genus of red algae (phylum Rhodophyta). ... Lemanea is the generic name for an alga of which there are two species in the British Isles:- Lemanea fluviatilis (L.) C.Ag. ... Binomial name (Linnaeus) Kuntze, 1891 Palmaria palmata (L.) Kuntze, also called Dulse, dillisk, dilsk or creathnach, is a red algae (Rhodophyta) previously referred to as Rhodymenia palmata (Linnaeus) Greville. ... Schmitzia hiscockiana Maggs and Guiry. ... Binomial name Chondrus crispus Stackhouse Irish moss, or carrageen moss (Irish carraigÃn, moss of the rock) is a species of red algae (Chondrus crispus) which grows abundantly along the rocky parts of the Atlantic coast of Europe and North America. ... Mastocarpus stellatus, also called ClÃºimhÃn Chait, Carragheen, or Carrageen Moss, is closely related to Irish Moss, or Chondrus crispus. ...

Pit connections and pit plugs

Pit connections

Pit connections and pit plugs are unique and distinctive features of red algae that form during the process of cytokinesis following mitosis. In red algae, cytokinesis is incomplete. Typically, a small pore is left in the middle of the newly formed partition. The pit connection is formed where the daughter cells remain in contact.

Shortly after the pit connection is formed cytoplasmic continuity is blocked by the generation of a pit plug, which is deposited in the wall gap that connects the cells.

Connections between cells having a common parent cell are called a primary pit connections. Because apical growth is the norm in red algae, most cells have two primary pit connections, one to each adjacent cell.

Connections that exist between cells not sharing a common parent cells are labeled secondary pit connections. These connections are formed when an unequal cell division produced a nucleated daughter cell that then fuses to an adjacent cell. Patterns of secondary pit connections can be seen in the order Ceramiales.

Pit plugs

After a pit connection is formed, tubular membranes appear. A granular protein, called the plug core, then forms around the membranes. The tubular membranes eventually disappear. While some orders of red algae simply have a plug core, others have an associated membrane at each side of the protein mass, called cap membranes. The pit plug continues to exist between the cells until one of the cells dies. When this happens, the living cell produce a layer of wall material that seals off the plug.

Function

It is thought that the pit connections function as structural reinforcement, and as an avenue for cell to cell communication and/or symplastic transport in red algae.^{[citation needed]} While the presence of the cap membrane could inhibit this transport between cells, it has been hypothesized that the tubular plug cores serve as a means of transport.

Consumption

Several species are used as food. Dulse (Palmaria palmata)^[7] and Porphyra are the best known in the British Isles. ^[8] Binomial name Palmaria palmata (Linnaeus) Kuntze, 1891 Dulse (Palmaria palmata (L.) Kuntze), also called dillisk, dilsk, dulse or creathnach, is a red alga (Rhodophyta) that grows on the northern coasts of the Atlantic and Pacific oceans. ... Binomial name (Linnaeus) Kuntze, 1891 Palmaria palmata (L.) Kuntze, also called Dulse, dillisk, dilsk or creathnach, is a red algae (Rhodophyta) previously referred to as Rhodymenia palmata (Linnaeus) Greville. ... Porphyra is a genus of red algae. ...

See also

The Heterokontophyta (Phaeophyta or brown algae, singular: brown alga) is a large group of mostly marine multicellular algae, including many seaweeds of colder Northern Hemisphere waters. ... Divisions Chlorophyta Charophyta Green algae are microscopic protists; found in all aquatic environments, including marine, freshwater and brackish water. ... A red tide off the coast of La Jolla, California. ... French phycologist and marine scientist, Mrs. ...

External links

References

^ D. Thomas (2002). Seaweeds. Life Series. Natural History Museum, London. ISBN 0-565-09175-1.
^ ^a ^b ^c W. J. Woelkerling (1990). "An introduction", in K. M. Cole & R. G. Sheath: Biology of the Red Algae. Cambridge University Press, Cambridge, 1–6. ISBN 0-521-34301-1.
^ ^a ^b M. D. Guiry. Rhodophyta: red algae. Retrieved on 2007-06-28.
^ N. J. Butterfield (2000). Bangiomorpha pubescens n. gen., n. sp.: implications for the evolution of sex, multicellularity, and the Mesoproterozoic/Neoproterozoic radiation of eukaryotes. Paleobiology 26 (3): 386–404.
^ Hwan Su Yoon, K. M. Müller, R. G. Sheath, F. D. Ott & D. Bhattacharya (2006). Defining the major lineages of red algae (Rhodophyta). Journal of Phycology 42: 482–492. doi:10.1111/j.1529-8817.2006.00210.x.
^ G. W. Saunders & M. H. Hommersand (2004). Assessing red algal supraordinal diversity and taxonomy in the context of contemporary systematic data. American Journal of Botany 91: 1494–1507.
^ Dulse: Palmaria palmata. Quality Sea Veg. Retrieved on 2007-06-28.
^ T. F. Mumford & A. Muira (1988). "Porphyra as food: cultivation and economics", in C. A. Lembi & J. Waaland: Algae and Human Affairs. Cambridge University Press, Cambridge. ISBN 0-521-32115-8.

Categories: All articles with unsourced statements | Articles with unsourced statements since April 2007 | Protista | Algae | Red algae For other similarly-named museums see Museum of Natural History. ... The headquarters of the Cambridge University Press, in Trumpington Street, Cambridge. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 179th day of the year (180th in leap years) in the Gregorian calendar. ... This article is about the journal. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... The American Journal of Botany (ISSN 00029122) is a peer-reviewed scientific journal which includes research papers on all aspects of plant biology. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 179th day of the year (180th in leap years) in the Gregorian calendar. ... The headquarters of the Cambridge University Press, in Trumpington Street, Cambridge. ...

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