Taxon Account

Cymbella C.A. Agardh; 1830; 1

Key references

Krammer K. 1982. Valve Morphology in the Genus Cymbella C.A. Agardh. Helmcke J.-G. & Krammer K. Micromorphology of Diatom Valves. Vol. XI, J. Cramer, Vaduz. 1-49 pp

Krammer K. 2002. Cymbella. Lange-Bertalot H. (ed), Diatoms of Europe, Diatoms of the European Inland Waters and Comparable Habitats, Vol.3, A.R.G. Gantner Verlag K.G., Ruggell. 584 pp

Morphology

Valves dorsiventral, in valve view with a convex dorsal margin, and an often convex, rarely straight or concave ventral margin, apices rounded or protracted, valves symmetrical to the transapical axis; frustules biconvex in girdle view.

Raphe often more or less central, so raphe sternum variously curved. Internal and external raphe fissures not superimposed, external central raphe branches ventrally bent and recurved, terminal fissures deflected dorsally. External central raphe endings straight or deflected, often expanded. Internal central raphe ending hidden by an overgrowth of silica (intermission absent), internal polar helictoglossae often markedly thickened when apical pore fields present.

One or several isolated pores often present on ventral side of central raphe endings, often close to the ventral striae, internally occluded by irregular ingrowths.

Striae uniseriate, areolae often resolvable in LM, shape of external areola openings varies between species and can be important for identification; internally areolae open in depressions between virgae, no hymenes or cribra (SEM).

Apical pore fields often present, seen as clear areas on the ventral side of the polar raphe fissure.
Species with apical pore fields able to attach by mucilage stalks; without apical pore fields free living.

Chloroplast usually a single double H with a central pyrenoid, pyrenoid lying on the dorsal side of the girdle.
Cymbella lanceolata has a single chloroplast with a central pyrenoid and many lobes coming off in different directions.

Literature

References are given in chronological order.

Reference
Citation
Agardh, C.A. 1830. Conspectus Criticus Diatomacearum. Part 1. Lundae. Litteris Berlingianis pp. 1-16. Morphology; Taxonomy; Description
Krammer K. 1982. Valve Morphology in the Genus Cymbella C.A. Agardh. Helmcke J.-G. & Krammer K. Micromorphology of Diatom Valves. Vol. XI, J. Cramer, Vaduz. 1-49 pp Morphology; Illustrations
Krammer K. 2002. Cymbella. Lange-Bertalot H. (ed), Diatoms of Europe, Diatoms of the European Inland Waters and Comparable Habitats, Vol.3, A.R.G. Gantner Verlag K.G., Ruggell. 584 pp ; Illustrations; Taxonomy; Morphology; Ecology
Kermarrec L., Ector L., Bouchez A., Rimet F., Hoffmann L. 2011. A preliminary phylogenetic analysis of the Cymbellales based on 18S rDNA gene sequencing. Diatom Research. 26(3): 305-315. Biology
da Silva W.J., Jahn R., Ludwig T.A.V., Hinz F., Menezes M. 2015. Typification and taxonomic status re-evaluation of 15 taxon names within the species complex Cymbella affinis/tumidula/turgidula (Cymbellaceae, Bacillariophyta). PhytoKeys. 53: 1-25. Morphology; Taxonomy; Illustrations
This page should be cited as:

Jüttner I., Cox E. J. Cymbella C.A. Agardh; 1830; 1. In: Jüttner I., Carter C., Chudaev D., Cox E.J., Ector L., Jones V., Kelly M.G., Kennedy B., Mann D.G., Turner J. A., Van de Vijver B., Wetzel C.E., Williams D.M.. Freshwater Diatom Flora of Britain and Ireland. Amgueddfa Cymru - National Museum Wales. Available online at https://naturalhistory.museumwales.ac.uk/diatoms/browsespecies.php?-recid=3705. [Accessed:  ].

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Record last modified: 23/07/2021