Hormosira (Endlichter), 1838: 368
Holotype species: Hormosira moniliformis Meneghini
Currently accepted name for the type species: Hormosira banksii (Turner) Decaisne
Taxonomic status: currently recognized as a distinct genus.
Description: Thallus to 20 (-30) cm long, consisting of branched chains of subspherical to elongate, bead-like segements. Small discoid holdfast. Growth from an apical meristem consisting of 4 apical cells and surrounding meristematic tissue. Thallus is parenchymatous and differentiated into a meristoderm of relatively small cells with numerous chloroplasts and physodes, a cortex of larger, vacuolate cells and a filamentous medulla surrounding a fluid or air-filled central space. Discoid chloroplasts lack pyrenoids. Life history is diplontic. Sexual reproduction is oogamous. Individuals are dioecious with conceptacles containing paraphyses (phaeophycean hairs) and antheridia or oogonia scattered over the thallus. Antheridia produce 64 spermatozoids, 7-15 µm in length. Spermatozoids are heterokont, possess an eyespot and are negatively phototactic. The anterior flagellum is 6.5 µm long and bears a blunt spine 2 µm back from the tip. The posterior flagellum is relatively long, 13 µm. Oogonia produce 4 eggs, 60-65 µm diameter and 4 sterile vestigial cells. Eggs secrete the sperm attractant, hormosirene.
Comments: Hormosira is endemic to the temperate regions of Australia and New Zealand.
NCBI Nucleotide Sequences
Numbers of names and species: There are 10 species (and infraspecific) names in the database at present, of which 1 has been flagged as currently accepted taxonomically.
Names: ('C' indicates a name that is currently 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):
Hormosira articulata (J.Agardh) Zanardini S
Hormosira banksii (Turner) Decaisne C
Hormosira banksii var. sieberii (Bory de saint-Vincent) Harvey S
Hormosira billardierii (Bory de Saint-Vincent) J.Agardh S
Hormosira gracilis Kützing S
Hormosira moniliformis Meneghini S - type
Hormosira nodularia (Mertens) Decaisne S
Hormosira pumila Kützing C
Hormosira sieberi (Bory de Saint-Vincent) Decaisne S
Hormosira triquetra (C.Agardh) Decaisne S
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: http://www.algaebase.org/search/genus/detail/?genus_id=42605
Cite this record as:
Guiry, M.D. & Guiry, G.M. 2013. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 12 December 2013.
Algaebase taxon LSID: urn:lsid:algaebase.org:taxname:7607