Heteronema Dujardin, 1841
Holotype species: Heteronema marinum 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.
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 2024-02-06 by E.A. Molinari Novoa.
Taxonomic status: This name is of an entity that is currently accepted taxonomically.
Gender: This genus name is currently treated as neuter.
Most recent taxonomic treatment adopted: Cavalier-Smith, T. (2016). Higher classification and phylogeny of Euglenozoa. European Journal of Protistology 56: 250–276, 2 figs.
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.
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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=50743
Citing AlgaeBase
Cite this record as:
E.A. Molinari Novoa in Guiry, M.D. & Guiry, G.M. 06 February 2024. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 22 November 2024