Discocyclus Rioual & Schultz, 2025

Publication details: Rioual & Schultz, 2025: 8

Original publication and holotype designation: Rioual, P., Schultz, K., Joh, G. & Liao, M. (2025). Cyclotella or Discostella? an evaluation of the morphological and molecular evidence regarding the generic placement of a centric diatom from eastern Asia and the creation of Discocyclus gen. nov. Taxonomy 5(17): 1–12, 4 figures, 1 table.

Description: A new genus of the Stephanodiscaceae. Cells solitary, frustules cylindrical in girdle view, circular in valve view. Initial cells lenticular. Valve face with two different morphological patterns, with radially striated marginal part that surrounds a distinctly different central area that can vary from almost flat to concentrically undulate, convex or concave. The central area has no central fultoportula. Internally, the marginal zone consists of radial simple alveolae with hyaline laminae covering the internal surface of the alveolae on the valve face. Alveolae open internally by oval foramina located at the face/mantle junction. Radiate alveolae are separated internally by costae. A single ring of fultoportulae occurs on the valve mantle. Mantle fultoportulae bearing two satellite pores in circumferential (lateral) position. One rimoportula located on the mantle on a costa within the ring of marginal fultoportulae. Externally, mantle/face junction broadly sloped, striated margin spans from central area to mantle edge, striae biseriate and separated by costae. Mantle fultoportulae outer openings are either simple or with well-developed tubular projections.

Information contributed by: Original description.. The most recent alteration to this page was made on 2025-03-31 by M.D. Guiry.

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

Gender: This genus name is currently treated as masculine.

Comments: Etymology of Discocyclus gen. nov.: this genus name is a combination of the genus names Discostella and Cyclotella, indicating that Discocyclus shares some morphological features of both genera.

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Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in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

Linking to this page: https://www.algaebase.org/search/genus/detail/?genus_id=55654

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 31 March 2025. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 03 April 2025