Netrium (Nägeli) Itzigsohn & Rothe, 1856
Holotype species: Netrium digitus (Brébisson ex Ralfs) Itzigsohn & Rothe
Original publication and holotype designation: Rabenhorst, L. (1856). Die Algen Sachsens. Exsiccata. Decades 1-100. . Dresden.
Taxonomic status: currently recognized as a distinct genus.
Most recent taxonomic treatment adopted: Guiry, M.D. (2013). Taxonomy and nomenclature of the Conjugatophyceae (=Zygnematophyceae). Algae. An International Journal of Algal Research 28: 1-29.
Netrium digitus, classically part of the Zygnematales, was determined to be sister to taxa traditionally classified among the Desmidiales (Hall et al. 2008: 471). - (21 Jun 2012) - Wendy Guiry
Description: Cell solitary, median sized to large (35-430 um long), elongate-cylindric, elliptic or fusiform (length 2-9 times width), straight, with broadly rounded or truncate ends. Chloroplasts elongate, 2 or 4 per cell, axial, stellate in end view, with 6-12 lateral, longitudinal ridges with smooth, notched or serrate margins. Pyrenoids several, rounded or elongate, in axial row or scattered. Nucleus between chloroplasts. Ultrastructurally, cell wall two-layered, without pores. Asexual reproduction by transverse cell division. Mature daughter cell morphology retained by elongation of severed end. Sexual reproduction by homothallic or heterothallic conjugation known for 5 species. In homothallic strains gametangia often sister cells from recent cell division. Zygote forms in broad conjugation tube; mature zygospore spherical with smooth or wrinkled mesospore wall. Karyogamy at germination, followed by meiosis, producing two gones. Mating type and zygospore morphology show Mendelian inheritance ratios. Netrium cosmopolitan; abundant in acidic, oligotrophic, aquatic habitats or in Sphagnum bogs, with occasional records from more basic habitats (e.g. N. minus in alpine pool, pH 8.0). Emended by Gontcharov & Melkonian (2010: 349).
Information contributed by: J.F. Gerrath. The most recent alteration to this page was made on 7 May 2013 by M.D. Guiry.
Numbers of names and species: There are 15 species names in the database at present, as well as 53 infraspecific names. Of the species names, 9 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.
Hall, J.D., Karol, K.G., McCourt, R.M. & Delwiche, C.F. (2008). Phylogeny of the conjugating green algae based on chloroplast and mitochondrial nucleotide sequence data. Journal of Phycology 44: 467-477.
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: 11 April 2002 by M.D. Guiry
Verified by: 07 May 2013 by M.D. Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=43557
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 23 January 2019.