Collinsiella& Gardner, 1903
Holotype species: Collinsiella tuberculata Setchell & N.L.Gardner
Original publication:Setchell, W.A. & Gardner, N.L. (1903). Algae of northwestern America. University of California Publications in Botany 1: 165-418, Plates 17-27.
Taxonomic status: currently recognized as a distinct genus.
Description: Gametophytic thalli enclosed in gelatinous matrix, initially disk-shaped, consisting of a packet of cells with true vegetative cell division; mature thalli definitely expanded, solid and firm, gelatinous, attached to substratum. Cells near upper frond surface pyriform or elliptical, more or less vertical and densely aggregated. Cells in center of frond larger than at surface, spherical to pyriform. Cells near lower surface spherical, with long rhizoidal appendage. Cells uninucleate, each with cup-shaped chloroplast usually opening at lower portion of cell and a single large pyrenoid. Cells surrounded by concentrically stratified sheath and attached by short, gelatinous, dichotomously-divided stalk to mother cell below, undergoing division perpendicularly, obliquely or in parallel to free surface of frond. Cell wall with positive cellulose reaction to iodine-zinc chloride reagent. Vegetative cells differentiate into gametangia producing 4-16 or 32 gametes. Sporophytic thalli microscopic, unicellular and spheroidal, with many rhizoids, and penetrating into shell; when mature, producing many pear-shaped, quadriflagellate zoospores (more than 32) that form gametophytic stage. Plants with sporic life history and isogamous sexual reproduction. Gametes pear-shaped, anteriorly biflagellate, after fusion developing into unicellular sporophyte.
Information contributed by: M. Chihara. The most recent alteration to this page was made on 23 May 2012 by Michael Guiry.
Comments: Collinsiella in North Pacific Ocean along Pacific Coast of North America and Japan, growing on rocks, pebbles and shells in tide pools in middle and upper littoral zones. Collinsiella with early developmental stages similar to Gomontia and Monostroma. Hence, Collinsiella possibly in Codiophylaceae sensu Kornmann. Other life history studies present possibility that Collinsiella is a life history stage of Enteromorpha (Ulvophyceae). Further studies, including ultrastructural observations required to determine systematic position of genus. Collinsiellaceae initially placed in Chlorosarcinales because of presence of a disc consisting of a packet of cells undergoing desmoschisis. More recently Chlorosarcinales limited to unicellular, colonial green algae with true vegetative cell division, however, it is a heterogeneous assemblage with various ultrastructural features. Accordingly, Collinsiella tentatively placed in Tetrasporales
Numbers of names and species: There are 3 species names in the database at present, of which 3 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):
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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: 28 December 2000 by M.D. Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=40885
Please cite this record as:
Guiry, M.D. & Guiry, G.M. 2020. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 26 February 2020.