Galaxaura J.V., 1812
Lectotype species: Galaxaura rugosa (J.Ellis & Solander) J.V.Lamouroux
Original publication:Lamouroux, [J.V.F.] (1812). Extrait d'un mémoire sur la classification des Polypiers coralligènes non entièrement pierreux. Nouveaux Bulletin des Sciences, par la Société Philomathique de Paris 3: 181-188.
Type designated in Schmitz, F. (1889). Systematische Übersicht der bisher bekannten Gattungen der Florideen. Flora oder Allgemeine botanische Zeitung 72: 435-456, pl. XXI.
Taxonomic status: currently recognized as a distinct genus.
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.
According to Huisman (2006: 21), the name is a classical one, one of the Oceanides, sea-nymph daughters of Oceanus and Tethys. - (24 Dec 2006) - Wendy Guiry
Description: Life history triphasic, with gametophytic and tetrasporophytic thalli dimorphic, differing in both gross habit and cortical-cell arrangements. Gametophytic fronds multiaxial, cylindrical, pseudo-dichotomously branched, with or without slightly segmented but non-constricted branches, whereas tetrasporic thalli covered with pigmented epidermal hairs/assimilatory filaments. Primary growth and the morphology of spermatangial conceptacles, procarps and cystocarp are similar to that found in Dichotomaria; however, the multinucleate fusion cell in Galaxaura incorporates more inner proximal gonimoblast cells (7-10) than that seen (3-4) in Dichotomaria. Its primary gonimoblast filaments form a conceptacle, in contrast to that found in Dichotomaria; the involucral filaments derived from the basal cell do not form a pericarp but are restricted to the base throughout the development of the cystocarp (Wang et al., 2005: 691, 692). Plants erect, dichotomously branched; branches terete to flattened, glabrous or covered with photosynthetic hairs, calcified, articulated or non-articulated, multiaxial. Medulla filamentous. Cortical structure gametophytes and tetrasporophytes dimorphic; gametophyte cortex three layered, inner one or two layers of large colorless cells often fused laterally, remaining outer cortex of progressively smaller pigmented cells; cortex of tetrasporophytes either essentially filamentous, with or without inflated basal cells supporting assimilatory filaments, or pseudoparenchymatous, of three to six layers; inner cortex of one to three layers of large colorless cells; cells of the outermost layer borne on smaller pigmented supporting cells with calcification of the gaps between the supporting cells. Monoecious or dioecious. Spermatangia formed in subcortical cavities. Carpogonial branches 3-celled, replacing vegetative filaments. Prior to fertilization the hypogynous cell and basal cell each produce three to four sterile branches, the sterile branches making a minor contribution to the conceptacle wall. Gonimoblast initiated from carpogonium and forming most of the immersed cystocarp wall. Fusion cell formed from carpogonium, hypogynous cell, basal cell and part of conceptacle wall filaments. Carposporangia terminal on gonimoblast filaments that radiate from conceptacle wall toward center of cystocarp. Tetrasporangia cruciately divided, either lateral or terminal on assimilatory filaments, lateral on cells supporting outer cortex, or terminal on outer cortical cells.
Information contributed by: R.B. Searles. The most recent alteration to this page was made on 20 Jan 2017 by M.D. Guiry.
Comments: Mostly tropical to subtropical, a few species in temperate waters, low tide line to deep subtidal.
Numbers of names and species: There are 106 species names in the database at present, as well as 9 infraspecific names. Of the species names, 25 have been flagged as accepted taxonomically on the basis of the listed literature under the species name. In some instances, opinions on taxonomic validity differ from author to author and users are encouraged to form their own opinion. AlgaeBase is a work in progress and should not be regarded as a definitive source only as a guide to the literature..
Names: ('C' indicates a name that is accepted taxonomically; 'S' a homotypic or heterotypic synonym; 'U' indicates a name of uncertain taxonomic status, but which has been subjected to some verification nomenclaturally; 'P' indicates a preliminary AlgaeBase entry that has not been subjected to any kind of verification. For more information on a species click on it to activate a link to the Species database):
Click here to also show infraspecific names in the list below.
Verification of data
Users are responsible for verifying the accuracy of information before use, as noted on the website Content page.
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.
Created: 01 January 2001 by M.D. Guiry
Verified by: 20 January 2017 by M.D. Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=34150
Please cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2019. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 24 January 2019.