Pachycladella P.C.Silva, 1970

Holotype species: Pachycladella umbrina (G.M.Smith) P.C.Silva

Original publication and holotype designation: Silva, P.C. (1970). Remarks on algal nomenclature. IV. Taxon 19: 941-945.

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Description: Solitary spherical to slightly quadrangular or lobate, microscopic cells not embedded in gelatinous envelope. Cells 3-13 &m diameter, with four (or more) cruciate or tetrahedrally arranged tubular or slightly conical processes. Processes more or less the same length on each cell, 5-120 &m long and 2-4 &m wide at base, translucent to dark brown, with usually a slightly bifurcate or sometimes blunt apex. Processess sometimes distinguished by darker colour than the cell wall. They are structurally non identical to the cell wall and and can be mechanically separated from it. In culture (in P. umbrina only), processes translucent. Details of process formation not yet clarified. Cells uninucleate; single chloroplast cup-shaped and parietal, nearly filling the cell; pyrenoid single and carved with several spoke-like invaginations (in P. umbrina and P. zatoriensis). Asexual reproduction by zoospores. Basal bodies of biflagellate cell at 1 and 7 o'clock positions (clockwise orientation). Sexual reproduction unknown. Pachycladella planktonic in freshwater, one species found on snow, rare but cosmopolitan. Bernardia tetraedriaca Playfair (1918) is probably representative of Pachycladella zatoriensis. P. umbrina and P. zatoriensis investigated by TEM, and microanalysis reveals presence of Fe and Fe and Mn respectively on processes, and not on cell wall. Other taxa rare and require further investigations to confirm status in Pachycladella.

Information contributed by: O.L. Reymond & D. Garbary. The most recent alteration to this page was made on 2012-07-09 by Michael Guiry.

Taxonomic status: This name is of an entity that is currently accepted taxonomically.

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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Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in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.

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Cite this record as:
Michael Guiry in Guiry, M.D. & Guiry, G.M. 09 July 2012. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 20 April 2024