Gigartina Stackhouse, 1809
Holotype species: Gigartina pistillata (S.G.Gmelin) Stackhouse
Original publication and holotype designation: Stackhouse, J. (1809). Tentamen marino-cryptogamicum, ordinem novum; in genera et species distributum, in Classe XXIVta Linnaei sistens. Mémoires de la Société Imperiale des Naturalistes de Moscou 2: -97.
Description: Plants of the largest species reach over 100 cm in length. Thalli for the most part are erect and range from broadly foliose to narrowly pinnate. A few species form entangled clumps anchored by multiple haptera. Cystocarps are 95 conspicuously protuberant on marginal and/or surface proliferations and contain a filamentous hull surrounding the carposporophyte. Ultrastructural studies of cells involved in the production of carposporophytes and carposporangia have been made by Tsekos and Schnepf (1983) and Tsekos (1983). Tetrasporangia form in intercalary chains at the border of cortex and medulla. Guiry (1984) compared the formation of tetrasporangial sori in the type species with with other members of the genus and concluded that the differences point to there being more than one genus involved in the complex.
Information contributed by: G.T. Kraft. The most recent alteration to this page was made on 2017-01-23 by M.D. Guiry.
Taxonomic status: This name is of an entity that is currently accepted taxonomically.
Most recent taxonomic treatment adopted: Schneider, C.W. & Wynne, M.J. (2007). A synoptic review of the classification of red algal genera a half a century after Kylin's "Die Gattungen der Rhodophyceen". Botanica Marina 50: 197-249.
Comments: Because of their commercial importance, Gigartina spp. have been subjects of much recent study. The ecology of estuarine and open coast populations of the one northeastern Atlantic species was investigated by Mathieson and Tveter (1976) in relation to amounts and quality of their carrageenan. Studies of photoperiodic responses (Guiry 1984; Guiry and Cunningham 1984) have identified reproductive "windows" and suggested explanations for the increasingly exclusive vegetative propagation, as opposed to gametangial and tetrasporangial production, in high-latitude populations of a widespread European species. Genetic determination of branching patterns and upper limits of temperature tolerance have been established for several species by Guiry et al. (1987). Numerous carrageenan analyses (e.g., Parsons et al. 1977; West and Guiry 1982) have been made, as well as studies demonstrating that both normal "Polysiphonia" (Guiry 1984; Guiry et al. 1987; West and Guiry 1982) and apomictic (Chen et al. 1974; Masuda and Uchida 1976) life histories occur in the genus. The feasibility of cultivating species on artificial substrata has been assessed by Mumford and Waaland (1980) and shown to have commercial potential. Distribution: Worldwide throughout cool to cold temperate seas, a very few species occurring in the subtropics. Centers of particularly rich species diversity are California, Japan, New Zealand, Chile, and South Africa.
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Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in CD format. These AlgaeBase descriptions are now being continually updated, and each current contributor is identified above. The PSA and AlgaeBase warmly acknowledge the generosity of all past and present contributors and particularly the work of Dr Parker.
Descriptions of chrysophyte genera were subsequently published in J. Kristiansen & H.R. Preisig (eds.). 2001. Encyclopedia of Chrysophyte Genera. Bibliotheca Phycologica 110: 1-260.
Linking to this page: https://www.algaebase.org/search/genus/detail/?genus_id=33000
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 23 January 2017. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 09 December 2023