Metagoniolithon Weber, 1904
Lectotype species: Metagoniolithon charoides (J.V.Lamouroux) Weber Bosse
Currently accepted name for the type species: Metagoniolithon radiatum (Lamarck) Ducker
Original publication:Weber-van Bosse, A. (1904). Corallinaea verae of the Malay Archipelago. Siboga-Expeditie Monographie 61: 78-110, Plates XIV-XVI.
Type designated in Manza, A.V. (1937). The genera of the articulated corallines. Proceedings of the National Academy of Science of the United States of America 23: 44-48.
Taxonomic status: currently recognized as a distinct genus.
Most recent taxonomic treatment adopted: Kylin, H. (1956). Die Gattungen der Rhodophyceen. pp. i-xv, 1-673, 458 figs. Lund: C.W.K. Gleerups.
Description: Thalli comprising crustose holdfasts bearing branched and articulated fronds. Epilithic and epiphytic holdfasts attached with the aid of haustoria. Fronds of calcified, cylindrical intergenicula separated by uncalcified genicula. Branch apices covered by caps of mucilaginous material; apical meristematic cells below caps separated from one another. Intergenicula of arching tiers of medullary cells of uniform height; surrounded by a photosynthetic cortex and a unistratose layer of epithallial cells. Genicula conspicuous and meristematic, branching dichotomously at branch apices and, except in one variety (M. chara var. dichotomum), subsequently producing secondary branches arranged more or less in whorls; intergenicula not branching. Genicular cells not in tiers. Cells in contiguous filaments often joined by fusions; secondary pit-connections lacking. Epithallial cells in intergenicula wider than tall, those in the genicula taller than wide. Trichocytes usually abundant. Reproductive cells formed within conceptacles on the lateral surfaces of intergenicula. Tetrasporangia initiated in cortical tissue in peripheral ring; cells inside ring (cavity cells) elongating and, eventually, disintegrating to form conceptacle chamber. Procarps forming in coherent patch below cap and disintegrating cortical cells; roof formed by overarching filaments. Each carposporangial conceptacle containing a thin, broad fusion cell producing gonimoblast filaments from its periphery. Spermatangial conceptacles apparently develop in a similar manner, with spermatangia forming on the conceptacle floor in low chambers. Details of spore germination unknown.
Information contributed by: H.W. Johansen. The most recent alteration to this page was made on 15 Jul 2016 by Wendy Guiry.
Comments: Metagoniolithon contains three species endemic to western and southern Australia where they are common on rocks, algae, and seagrasses. Holdfasts of M. stelliferum attached to the seagrass Amphibolis via an intermediate host: a species of Fosliella epiphytic on the seagrass. Haustoria of Metagoniolithon extend through the thin Fosliellato directly contact the seagrass epidermal cells. Metagoniolithon, the only genus is the Metagoniolithoideae, shares some important characters with Amphiroa, such as conceptacle development, but differs markedly from that genus in many other characteristics, such as cells being joined by fusions rather than secondary pit-connections.
Numbers of names and species: There are 10 species names in the database at present, as well as 1 infraspecific names. Of the species names, 3 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.
Rösler, A., Perfectti, F., Peña, V. & Braga, J.C. (2016). Phylogenetic relationships of Corallinaceae (Corallinales, Rhodophyta): taxonomic implications for reef-building corallines. Journal of Phycology 52(3): 412-431.
Ducker, S.C. (1979). The genus Metagoniolithon Weber-van Bosse (Corallinaceae, Rhodophyta). Australian Journal of Botany 27: 67-101, 15 figs.
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: 15 July 2016 by Wendy Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=34584
Please cite this record as:
Wendy Guiry in Guiry, M.D. & Guiry, G.M. 2020. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 04 December 2020.