Characiopsis Borzì, 1895
Holotype species: Characiopsis minuta (A.Braun) Borzì
Currently accepted name for the type species: Pseudocharaciopsis minuta (A.Braun) Hibberd
Original publication and holotype designation: Borzí, A. (1895). Studi algologici: saggio di richerche sulla biologia delle alghe. Fasc. II. pp. -378, pls X-XXXI. Palermo: Alberto Reber Libreria Carlo Clausen.
Taxonomic status: currently regarded as a synonym of Pseudocharaciopsis.
Most recent taxonomic treatment adopted: Ott, D.W. & Oldham-Ott, C.K. (2003). Eustigmatophyte, Raphidophyte, and Tribophyte. In: Freshwater Algae of North America, Ecology and Classification. (Wehr, J.D. & Sheath, R.G. Eds), pp. 423-470. San Diego: Academic Press.
Description: Unicellular, solitary organisms sometimes in dense populations attached to different substrata sometimes directly by the cell base, sometimes by a basal cushion, sometimes by a stipe of variable length. Stipes robust or fragile, mostly entire only rarely with cytoplasm. Sometimes there is an attachment disk. In certain species the cell is aligned with the stipe or pedicel, whereas in others, the cell is at an angle to the attachment system. This can be at right angles. In addition, the stipe may be lateral. Cells 15-90 _m long and 2.5-12 _m wide with extremely variable morphology globular, ovoid, obovoid, ellipsoidal, fusiform, cylindrical, rod- or tear-shaped; during development often narrowing to base and apex. Cells frequently curved or with very irregular outline. Cell wall thin or thick, sometimes robust and even stratified and smooth. Extreme apex often with wart or cap-like thickening, or even a delicate or strong spine. Cells generally uninucleate but sometimes multinucleate, the latter undoubtedly associated with mature individuals prior to reproduction. Chloroplasts single to numerous, parietal or central, discoid, plate-like and sometimes folded or ribbon-shaped, occasionally even polygonal when numerous and pressed one against another; very rarely plate-like and perforate or even reticulate. Chloroplasts yellow green but often very pale and difficult to perceive. Pyrenoids known only in one species. Reserve products of oil droplets and lipids, sometimes red colored. Asexual reproduction by means of zoospores and aplanospores although the latter is very rare. Zoospores formed in twos or fours (rarely more) by the mother cell and released by a rupture of the cell wall without the formation of a true operculum. Zoospores with two unequal flagella. Characiopsis attached to different kinds of substrata, primarily sessile or non filamentous algae, but also on planktonic algae and the roots of small floating macrophytes. Genus cosmopolitan in freshwater, in temporary ponds, artificial lakes and tanks associated with fish culture. Species distinguished based on cell morphology and dimensions, presence or absence of a stipe, the number and form of chloroplasts and habitat. Characiopsis has been confused with the chlorococcalean green algae genus Characium which is distinguished by having starch and two equal flagella. It also resembles other Tribophyceae Characidiopsis Pascher which is characterized by presence of contractile vacuoles and a stigma, and Peroniella which is always globular and in which the stipe is always hollow and full of cytoplasm. According to Pizarro there are large differences in size between European taxa and those of other regions, especially those from the southern hemisphere.
Information kindly contributed by H. Pizarro but may now be outdated.
Numbers of names and species: There are 106 species names in the database at present, as well as 53 infraspecific names. Of the species names, 87 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: 11 April 2002 by M.D. Guiry
Verified by: 14 October 2016 by M.D. Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=43814
Please cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2021. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 24 January 2021.