''Bangia'' is an extant genus of division

Rhodophyta 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 within over 900 genera amidst ongoing taxonomic revisions. ...

that grows in marine or

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...

habitats. ''Bangia'' has small thalli with rapid growth and high reproductive output, and exhibits behavior characteristic of

r-selected In ecology, selection theory relates to the selection of combinations of traits in an organism that trade off between quantity and quality of offspring. The focus on either an increased quantity of offspring at the expense of reduced individua ...

species. The plants are attached by down-growing

rhizoid Rhizoids are protuberances that extend from the lower epidermal cells of bryophytes and algae. They are similar in structure and function to the root hairs of vascular land plants. Similar structures are formed by some fungi. Rhizoids may be un ...

s, usually in dense purple-black to rust-colored clumps. The chloroplasts of ''Bangia'', like others in the division Rhodophyta, contain

chlorophyll a } Chlorophyll ''a'' is a specific form of chlorophyll used in oxygenic photosynthesis. It absorbs most energy from wavelengths of violet-blue and orange-red light, and it is a poor absorber of green and near-green portions of the spectrum. Chlorop ...

and sometimes chlorophyll d, as well as accessory pigments such as

phycobilin Phycobilins (from Greek: '' (phykos)'' meaning "alga", and from Latin: ''bilis'' meaning "bile") are light-capturing bilins found in cyanobacteria and in the chloroplasts of red algae, glaucophytes and some cryptomonads (though not in green a ...

pigments and

xanthophyll Xanthophylls (originally phylloxanthins) are yellow pigments that occur widely in nature and form one of two major divisions of the carotenoid group; the other division is formed by the carotenes. The name is from Greek: (), meaning "yellow", an ...

s. Depending on the relative proportions of these pigments and the light conditions, the overall color of the plant can range from green to red to purple to grey; however, the red pigment,

phycoerythrin Phycoerythrin (PE) is a red protein-pigment complex from the light-harvesting phycobiliprotein family, present in cyanobacteria, red algae and Cryptomonad, cryptophytes, accessory to the main chlorophyll pigments responsible for photosynthesis.The ...

, is usually dominant.

Species

*'' Bangia aeruginosa'' Sprengel *'' Bangia amethystina'' Kützing *'' Bangia anisogona'' Meneghini *'' Bangia annulina'' ( Roth) Sprengel *'' Bangia atropurpurea'' (

Mertens __NOTOC__ Mertens () is a surname of Flanders, Flemish origin, meaning "son of Merten" (Martin (name), Martin). It is the fifth most common name in Belgium with 18,518 people in 2008. Geographical distribution As of 2014, 43.4% of all known bearer ...

Bangia carnea ''Bangia'' is an extant genus of division Rhodophyta that grows in marine or freshwater habitats. ''Bangia'' has small thalli with rapid growth and high reproductive output, and exhibits behavior characteristic of r-selected species. The plants ...

'' ( Dillwyn) Harvey *'' Bangia coccineopurpurea'' Kützing *'' Bangia condensata''

Zanardini Giovanni Antonio Maria Zanardini (12 June 1804, Venice – 24 April 1878) was an Italian physician and botanist who specialized in the field of phycology. In 1831 he obtained his medical doctorate from the University of Padua, followed by a degree ...

*'' Bangia confervoides''

*'' Bangia crispula'' Chauvin *'' Bangia discoidea'' A.Aziz *'' Bangia dura''

*'' Bangia enteromorphoides'' E.Y.Dawson *'' Bangia fergusonii'' Grunow *'' Bangia ferruginea'' Kerner *'' Bangia flocculosa'' Schousboe *'' Bangia foetida'' Sprengel *'' Bangia foetida'' Steudel *'' Bangia foliacea'' Schousboe *'' Bangia fulvescens'' ( C.Agardh) J.Agardh *''

Bangia fuscopurpurea ''Bangia'' is an extant genus of division Rhodophyta that grows in marine or freshwater habitats. ''Bangia'' has small thalli with rapid growth and high reproductive output, and exhibits behavior characteristic of r-selected species. The plants ...

'' ( Dillwyn) Lyngbye **'' Bangia fuscopurpurea f. viridis'' Wittrock & Nordstedt **'' Bangia fuscopurpurea var. concatenata'' Kützing **'' Bangia fuscopurpurea var. crinalis'' De Notaris **'' Bangia fuscopurpurea var. crispa''

Holmes Holmes may refer to: People and fictional characters * Holmes (surname), a list of people and fictional characters ** Sherlock Holmes, a fictional detective * Holmes (given name), a list of people * Gordon Holmes, a penname used by Louis Trac ...

& Batters **'' Bangia fusco-purpurea var. fuscenses'' W.J.Hooker **'' Bangia fuscopurpurea var. jadertina'' Kützing **'' Bangia fuscopurpurea var. pilosella'' Ardissone **'' Bangia fuscopurpurea var. setacea'' Kützing *'' Bangia gloiopeltidicola'' Tanaka *'' Bangia grateloupicola'' P.Crouan & H.Crouan *'' Bangia halymeniae'' M.J.Wynne *'' Bangia harveyi'' Areschoug *'' Bangia homotrichoides'' Kützing *'' Bangia intricata'' Brébisson & Godey *'' Bangia intricata'' Suhr ex Rabenhorst *'' Bangia kerkensis'' Meneghini *'' Bangia lacustris'' Carmichael *'' Bangia lanuginosa'' Harvey *'' Bangia latissima'' Meneghini *'' Bangia malacensis'' ( Kützing) Kützing *'' Bangia maxima'' Gardner *'' Bangia punctulata'' Schousboe *'' Bangia purpurea'' Schousboe *'' Bangia quadripunctata'' Lyngbye *'' Bangia radicula'' B.F.Zheng & J.Li *'' Bangia sericea'' Bory *'' Bangia simplex'' A.H.S.Lucas *'' Bangia tanakae'' Pham-Hoàng Hô *'' Bangia tavarisii'' Welwitsch *'' Bangia tenuis'' N.L.Gardner *'' Bangia thaerasiae'' Bory *'' Bangia trichodes'' Schousboe *'' Bangia vermicularis'' Harvey *'' Bangia viridis'' Lyngbye *'' Bangia yamadae'' Tanaka

Description

''Bangia'' is a red alga that arises from a discoid holdfast and short stipe consisting of the extensions of rhizoidal cells. Bangia has unbranched, erect thalli forming initially uniseriate filaments becoming multiseriate at maturity. The plant is composed of filiform, unbranched cylinders of cells embedded in a firm gelatinous matrix. The cell contains a stellate chloroplast with prominent pyrenoid, as well as single thylakoids (characteristic of division Rhodophyta). The growth of ''Bangia'' is diffuse and intercalary, and each cell is quadrate to rectangular in shape. Primary pitt connections are absent in all but the conchocelis stage.

Distribution

''Bangia'' grows in freshwater or in marine habitats, usually forming dense clumps or mats, and occur throughout the intertidal area and subtidally to the maximum depth at which benthic algae occur. The plants are usually attached to a solid substratum (rock or shell), but can also occur as epiphytes attached to other algae.

Ecology

Marine populations of ''Bangia'' in the Atlantic Ocean are common food for the periwinkle ''

Littorina littorea The common periwinkle or winkle (''Littorina littorea'') is a species of small edible whelk or sea snail, a marine gastropod mollusc that has gills and an operculum, and is classified within the family Littorinidae, the periwinkles. This is a ...

''.

Reproduction

Species of ''Bangia'' undergo a heteromorphic alternation of generation life cycle in which the haploid generation is dominant. Reproduction can be either sexual or asexual; sexual plants occur mainly during the cold season of the year, while at other times the thalli often bear monosporangia only. Bangia, like all Rhodophytes, lack motile sperm and so depend upon water currents to transport their gametes to the trichogyne (receptive area of the female gamete or carpogonium). All sexual reproduction in rhodophytes is oogamous. Carposporangia are formed through direct division of the zygote.

Carpospore A carpospore is a diploid spore produced by red algae Red algae, or Rhodophyta (, ; ), make up one of the oldest groups of eukaryotic algae. The Rhodophyta comprises one of the largest Phylum, phyla of algae, containing over 7,000 recognized spe ...

s germinate to form the diploid filamentous conchocelis phase, which produces conchosporangial branches bearing conchosporangia, each containing a single conchospore. These conchospores then germinate to form gametophytes. During the "conchocelis stage", the plants can also self-replicate using monospores. The monospores develop directly into new plants and may germinate within the sporangia.

Scientific interest

Silicified peritidal carbonate rocks have been found off Somerset Island, arctic Canada, which contain fossils of well-preserved bangiophyte red algae ('' Bangiomorpha''). Because these fossils have multiseriate filaments derived by longitudinal divisions from uniseriate filaments, taxonomists believe that these fossils are related to ''Bangia''. This resolution distinguished these fossils from other pre-Ediacaran eukaryotes and contributes to evidence that multicellular algae diversified before the Ediacaran radiation of large animals.

Related genera

'' Bangiadulcis'' and '' Pseudobangia'' were previously thought to be part of the genus ''Bangia''. However, it has since been discovered that these plants can only undergo asexual reproduction through the formation of archaeosporangia. In fact, sexual reproduction has so far only been recorded in ''Bangia'', '' Porphyra'', '' Erythrotrichia'' and '' Erythrocladia''.

Etymology

The genus was named after Niels Hofman Bang (1803–1886), the Danish patron of Hans Christian Lyngbye, who described the genus.

References

* Brodie, Juliet A., and Irvine, Linda M. “Volume I Rhodophyta Part 3B Bangiophycidae.” Seaweeds of the British Isles. The Natural History Museum. St. Edmundsbury Press Ltd., 2003. pp 91–92 * Butterfiled, Nicholas J; Knoll, Andrew H; Sweet, Keene. “A Bangiophyte Red Alga from the Proterozoic of Arctic Canada.” Science, New Series, Vol. 250, No. 4977, 1990. pp 104–107 * Fritsch, F.E. “Structure and Reproduction of the Algae Volume II.” Cambridge University Press 1945. pp 397–398, 415, 423-424, 431, 433-435 * Garbary, David, J; Hansen, Gayle I; Scagel, Robert F. “The Marine Algae of British Columbia and Northern Washington: Division Rhodophyta (Red Algae), Class Bangiophyceae.” Dept. of Botany, University of British Columbia, Vancouver, Canada. 1980. pp 139–142 and 164-165