153,840 species and infraspecific names are in the database, 21,012 images, 59,576 bibliographic items, 413,468 distributional records.

Batrachospermum Roth, 1797

Classification:
Empire Eukaryota
Kingdom Plantae
Subkingdom Biliphyta
Phylum Rhodophyta
Subphylum Eurhodophytina
Class Florideophyceae
Subclass Nemaliophycidae
Order Batrachospermales
Family Batrachospermaceae

Holotype species: Batrachospermum gelatinosum (Linnaeus) De Candolle

Original publication and holotype designation: Roth, A.W. (1797). Bemerkungen über das Studium der cryptogamischen Wassergewächse. : [1]6-109 [Druckfehler].
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Taxonomic status: currently recognized as a distinct genus.

Most recent taxonomic treatment adopted: Sheath, R.G. (2003). Red Algae. In: Freshwater Algae of North America, Ecology & Classification. (Wehr, J.D. & Sheath, R.G. Eds), pp. 197-224. San Diego: Academic Press.

Nomenclatural notes
Batrachosperma, as used by Bory, appears to be an orthographic variant of Batrachospermum and seems to be correctable. All instances of the former spelling has been changed to the latter. INA: "Invalid: orthographic variant of Batrachospermum Roth 1797". - (5 Apr 2017) - M.D. Guiry

Taxonomic notes
Emended by Entwisle, M.L. Vis, W.B. Chiasson, Necchi & A.R. Sherwood (2009: 709) and a new combination made: Batrachospermum section Macrospora (Kumano) Entwisle, M.L. Vis, W.B. Chiasson, Necchi & A.R. Sherwood. - (17 Feb 2010) - Wendy Guiry

Description: Gelatinous gametophyte filaments, up to 40 cm long, with beaded appearance, varying from blue-green, olive, violet, grey to brownish. Uniseriate central axis with large cylindrical cells; 4-6 pericentrals produce repeatedly branched fascicles of limited growth. Rhizoid-like cortical filaments typically develop from lower side of pericentral cells. Cortical filaments grow downward and ensheathe axial cells; often produce secondary fascicle branches. Each fascicle cell contains several, ribbon-like, parietal chloroplasts with no pyrenoid. Few species form monospores in this stage. Spermatangia budded off terminal primary and secondary fascicle cells or in some species from involucral filaments of carpogonial branch; spherical, colorless, 4-8 µm diam. Carpogonial branches mostly little modified but twist in section Contorta. Carpogonia with broad trichogyne sometimes stalked on small base containing the nucleus. Carposporophytes generally spherical, compact or loose mass of gonimoblast filaments; carposporangia formed at apices. Carpospores germinate into chantransia (= pseudochantransia) stage, a crustose growth consisting of large basal cells and erect, sparsely branched filaments. Filaments can form monosporangia or divide meiotically, producing an attached gametophyte and 2 residual cells. Chromosome number n =2-ca. 22. Typical red algal cell ultrastructure. Pit plugs with 2 cap layers, outer one inflated. Chloroplast with single thylakoids which fragment and dilate and prolameller-like bodies formed during prolonged darkness. Mitosis with partially dispersed nuclear envelope, polar gaps, bipartite nuclear associated organelle and perinuclear E. R. Cytokinesis by infurrowing. Portions of reproduction studied with E. M. In B. boryanum, 5S rRNA indicates primitive status among florideophytes. Mucilage composed of neutral and acidic nonsulfated oligosaccharides. ADPG transferase probably the controlling enzyme in floridean starch formation. Glycine and serine are early products of 14C-labelling, followed by floridoside and trehalose. Photosynthetic rates range from 0.5-24 µmol g-1 fw h-1, and B. gelatinosum is saturated at 250 µmol m-2s-1 white light with optimum temperature of 15%C.Gelatinous gametophyte filaments, up to 40 cm long, with beaded appearance, varying from blue-green, olive, violet, grey to brownish. Uniseriate central axis with large cylindrical cells; 4-6 pericentrals produce repeatedly branched fascicles of limited growth. Rhizoid-like cortical filaments typically develop from lower side of pericentral cells. Cortical filaments grow downward and ensheathe axial cells; often produce secondary fascicle branches. Each fascicle cell contains several, ribbon-like, parietal chloroplasts with no pyrenoid. Few species form monospores in this stage. Spermatangia budded off terminal primary and secondary fascicle cells or in some species from involucral filaments of carpogonial branch; spherical, colorless, 4-8 µm diam. Carpogonial branches mostly little modified but twist in section Contorta. Carpogonia with broad trichogyne sometimes stalked on small base containing the nucleus. Carposporophytes generally spherical, compact or loose mass of gonimoblast filaments; carposporangia formed at apices. Carpospores germinate into chantransia (= pseudochantransia) stage, a crustose growth consisting of large basal cells and erect, sparsely branched filaments. Filaments can form monosporangia or divide meiotically, producing an attached gametophyte and 2 residual cells. Chromosome number n =2-ca. 22. Typical red algal cell ultrastructure. Pit plugs with 2 cap layers, outer one inflated. Chloroplast with single thylakoids which fragment and dilate and prolameller-like bodies formed during prolonged darkness. Mitosis with partially dispersed nuclear envelope, polar gaps, bipartite nuclear associated organelle and perinuclear E. R. Cytokinesis by infurrowing. Portions of reproduction studied with E. M. In B. boryanum, 5S rRNA indicates primitive status among florideophytes. Mucilage composed of neutral and acidic nonsulfated oligosaccharides. ADPG transferase probably the controlling enzyme in floridean starch formation. Glycine and serine are early products of 14C-labelling, followed by floridoside and trehalose. Photosynthetic rates range from 0.5-24 µmol g-1 fw h-1, and B. gelatinosum is saturated at 250 µmol m-2s-1 white light with optimum temperature of 15%C. Emended by Entwisle, M.L. Vis, W.B. Chiasson, Necchi & A.R. Sherwood (2009: 709) to exclude the section Contorta Skuja [including a synonym section Hybrida De Toni].

Information contributed by: R.G. Sheath. The most recent alteration to this page was made on 3 Jul 2017 by M.D. Guiry.

Comments: Cosmopolitan genus in moderately flowing, reasonably unpolluted streams; ca. 31% of North American 1st-4th order streams (mean current velocity 19 cm s-1). B. keratophytum common in bogs. Breaking stress, stretching, and drag are important ecologically. Both euryphotic (e.g. B. gelatinosum), and shade or brown water (e.g. B. keratophytum) species exist. Filament fragments common in guts of grazing amphipods, insect larvae and snails. Contorta section mostly concentrated in tropical to subtropical regions. B. gelatinosum, the only widespread species in tundra, tolerates large range of conditions: temp. 0-24%C, current velocity 7-181 cm s-1, pH 4.1-8.2, specific conductance 10-360 &S cm-1, PO4 <1-4900 &g 1-1. Lack of tetrasporic meiosis may be an adaptation to unidirectional flow; gametophytes produced seasonally from perennial chantransia stage, remaining upstream where conditions are more favorable than deep, slow flowing, turbid rivers. Fertilization may occur in turbulent eddies downstream; ca. 500 spermatia released for each carpogonium in dioecious B. boryanum with a mean fertilization rate of 22%. Carposporophytes may be released and travel up to 35 m downstream.

Genus considered to include species formerly classified in Sirodotia Kylin, Tuomeya Harvey and Nothocladus Skuja by Necchi and Entwisle (1990) but this proposal is not universally accepted.

Common names

(as Batrachospermum)
Swedish: Pärlbandsalger (Tolstoy & Österlund 2003).

Numbers of names and species: There are 273 species names in the database at present, as well as 116 infraspecific names. Of the species names, 82 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.

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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.

Created: 28 December 2000 by M.D. Guiry

Verified by: 03 July 2017 by M.D. Guiry

Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=42771

Citing AlgaeBase
Please cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2018. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 13 December 2018.

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