Hormotilopsis Trainor & H.C.Bold, 1954: 758
Holotype species: Hormotilopsis gelatinosa Trainor & H.C.Bold
Original publication and holotype designation:Trainor, F.R. & Bold, H.C. (1954). Three new unicellular Chlorophyceae from soil. American Journal of Botany 40: 758-767.
Taxonomic status: currently recognized as a distinct genus.
Description: Colonial pseudofilamentous, branching thalli with cells terminal in lamellate mucilaginous strands, either single or in groups of two or four. Cells spherical to ovoid, mostly 8-15 &m with some cells enlarged to 18 or 30 &m (H. gelatinosa and H. tetravacuolaris respectively). Cell walls smooth. Cells uninucleate with 2-4 contractile vacuoles, these becoming unclear in older cells. Chloroplast single and parietal with one basal pyrenoid surrounded in starch sheath. Asexual reproduction by autospores and zoospores; 2-4 per sporangium; released by rupture of sporangium. Zoospores with four equal, anterior flagella, 8-20 x .6-7 &m, ovoid to cylindrical with stigma. Details of zoospore ultrastructure described O'Kelly and others. Sexual reproduction unknown. Hormotilopsis isolated from soil; H. gelatinosa widely distributed (North America, former USSR, Japan), H. tetravacuolaris reported only from Cuba; both species available in culture from UTEX (strains 104 and 946). Species distinguished based on cell size and number of contractile vacuoles per cell. In previous tretaments genus assigned to Gloeodendraceae in Gloeodendrales (Ettl and Gärtner); more recently ultrastructural studies of H. gelatinosa and H. tetravacuolaris show similarities with Chaetopeltis and justify assignment to Chaetopeltidaceae. Phyllogloea considered distinct by O'Kelly and others based on ultratructural features, however, complete diagnosis not provided.
Numbers of names and species: There are 2 species (and infraspecific) names in the database at present, of which 2 have 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):
O'Kelly, C.J., Watanabe, S. & Floyd, G.L. (1994). Ultrastructure and phylogenetic relationships of Chaetopeltidales ord. nov. (Chlorophyta, Chlorophyceae). Journal of Phycology 30: 118-128.
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=44560
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2013. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 22 May 2013.
Algaebase taxon LSID: urn:lsid:algaebase.org:taxname:6416