Himantothallus Skottsberg, 1907
Holotype species: Himantothallus spiralis Skottsberg
Currently accepted name for the type species: Himantothallus grandifolius (A.Gepp & E.S.Gepp) Zinova
Original publication and holotype designation: Skottsberg, C. (1907). Zur Kenntnis der subantarktischen und antarktischen Meeresalgen. I. Phaeophyceen. In: Wissenschaftliche Ergebnisse der Schwedischen Südpolar-Expedition 1901-1903 unter Leitung von Dr. Otto Nordenskjöld. Vol. 4: 1, Part 6. ( Eds), pp. 1-172. Stockholm: Lithographisches Institut des Generalstabs.
Request PDFDescription: Massive thallus to 8 m long with a large hapteroid holdfast up 10 cm in diameter, a flattened and/or twisted stipe to 40 cm long and linear leathery fronds up to 40 cm broad and more or less ruffled. Juveniles have a trichothallic meristem, with growth in older blades being intercalary and diffuse and also occurring in the meristoderm.
Thallus structure is parenchymatous and differentiated into a meristoderm with box-like cells containing numerous chloroplasts, a larger-celled cortex and a medulla of longitudinal sheathed hyphae surrounded by a network of filaments. Discoid chloroplasts lack pyrenoids.
Life history is haplodiplontic. Macrothalli are sporophytes producing unilocular meiosporangia amongst the outer cells of the thallus. Meiospores are heterokont, 4-5 µm long, possess one chloroplast with an eyespot, and develop into dioecious filamentous gametophytes. Male gametophytes have relatively small cells, 10 µm wide ( 5-14µm long. Cells of female gametophytes are larger, 18-23 µm wide and 11-28 µm long. Sexual reproduction is oogamous. Antheridia develop in clusters, measure 3 x 10 µm, and each releases one sperm 3.5-4 µm in length. The anterior flagellum is shorter than the posterior flagellum. Oogonia measure 20-45 x 13 µm and release a single egg, 20 µm in diameter, through an apical aperture. In culture, unfertilized eggs develop may parthenogenetically into sporophytes.
Information contributed by: M.N. Clayton & M.D. Guiry. The most recent alteration to this page was made on 2014-06-20 by M.D. Guiry.
Taxonomic status: This name is of an entity that is currently accepted taxonomically.
Most recent taxonomic treatment adopted: Silberfeld, T., Rousseau, F. & Reviers, B. de (2014). An updated classification of brown algae (Ochrophyta, Phaeophyceae). Cryptogamie Algologie 35(2): 117-156, 1 fig., 1 table.
Comments: Himantothallus grows subtidally and is endemic to Antarctica and South Georgia.
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Contributors
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=45641
Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 20 June 2014. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 18 April 2024
