Heteronema Dujardin, 1841
Holotype species: Heteronema marina Dujardin
Original publication and holotype designation: Dujardin, F. (1841). Histoire naturelle des Zoophytes, Infusoires, comprenant la physiologie et la clasification de ces animaux et la manière de les étudier à l'aide du microscope. pp. i-xii, 1-684. Paris: Librarie Encyclopédique de Roret.
Taxonomic status: currently recognized as a distinct genus.
Most recent taxonomic treatment adopted: Cavalier-Smith, T. (2016). Higher classification and phylogeny of Euglenozoa. European Journal of Protistology 56: 250–276, 2 figs.
Description: Colorless, phagotrophic flagellates, (20)30-75(200) µm long, with ingestion organelle composed of separate rods associated with a subapical cytostome independent of the canal and reservoir; cell non-rigid, not flattened, euglenoid movement moderate, rarely pronounced. Two emergent flagella, unequal in length and thickness; the longer, thicker one directed anteriorly during swimming, with a coiling or flickering motion of the tip only, giving a characteristic gliding motion; the shorter, thinner one curving posteriorly, lying free from the cells.
Information contributed by: G.F. Leedale. The most recent alteration to this page was made on 28 Dec 2017 by M.D. Guiry.
Comments: This genus poses a taxonomic problem. Dujardin (1841) described a cell of variable shape with a single flagellum, an entity Bourrelly (1970) typifies as an Anisonema with euglenoid movement. Stein (1878) modified the generic description to encompass a cell with 2 flagella and described 2 species, one of which (H. acus) possesses ingestion rods. For Bourrelly, this organism cannot be separated from Peranema (Pseudoperanema). However, 25 or more species have now been described for the genus Heteronema, and Leedale (1967) based his order Heteronematales upon it. For him, Peranema (Pseudoperanema) differs from Heteronema in being flattened and having the trailing flagellum pressed closely to the cell. In fact, Peranema (Pseudoperanema) was also originally described as having a single flagellum (see Peranema (Pseudoperanema) for discussion of this problem). The genus Heteronema is included in Huber-Pestalozzi (1955), Starmach (1983), and Larsen and Patterson (1991). Common and widespread genus in freshwater ponds and brackish pools.
Numbers of names and species: There are 69 species names in the database at present, as well as 2 infraspecific names. Of the species names, 54 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: 31 August 2006 by M.D. Guiry
Verified by: 28 December 2017 by M.D. Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=50743
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 22 August 2019.