Taxon Account

Denticula Kützing; 1844; 43

Key references

Krammer K., Lange-Bertalot H. 1988. Süßwasserflora Mitteleuropas. Bacillariophyceae. 2. Teil. Bacillariophyceae, Epithemiaceae, Surirellaceae. Eds. Ettl H., Gerloff J., Heynig H., Mollenhauer D., Gustav Fischer Verlag, Stuttgart. 596 pp

Hamsher S.E., Graeff C.L., Stepanek J.G., Kociolek J.P. 2014. Frustular morphology and polyphyly in freshwater Denticula (Bacillariophyceae) species, and the description of Tetralunata gen. nov. (Epithemiaceae, Rhopalodiales). Plant Ecology and Evolution. 147(3): 346–365.

Morphology

Frustules isopolar; linear, linear-elliptical or lanceolate in valve view, with bluntly rounded or very slightly rostrate poles; rectangular with rounded corners in girdle view; girdle deep (hence cells often lie in girdle view).

Frustules isovalvar, diagonally (rotationally) symmetrical about the median valvar plane, as in most Nitzschia (i.e. the raphe systems of the two valves are diagonally opposite, rather than on the same side of the cell).

Striae uniseriate or biseriate (multiseriate in two species currently assigned to the genus but probably not belonging there [D. rainierensis and D. jamesrossensis]), parallel throughout; some ribs (interstriae) greatly thickened to form wall-like partitions (sometimes called ‘costae’) that traverse the valve from margin to margin; areolae circular.

Axial area narrow, central area absent.

Raphe slightly eccentric to marginal (and on opposite sides of the frustule in the two valves), sometimes raised on a slight, rounded keel; subtended by fibulae, which are formed where the wall-like partitions cross beneath the raphe; the bases of the fibulae are expanded in the apical direction to form flanges that restrict access to the raphe canal to elliptical holes (portulae); central raphe endings present or absent; polar raphe endings turned or hooked towards either the nearer (proximal) or farther (distal) valve margin.

Bands open; some species have ‘half-bands’ (bands that occupy only one side of the frustule; the most advalvar band(s) are modified to fit around and grip the transapical wall-like partitions.

Two plate-like chloroplasts per cell, arranged ‘fore and aft’ (one towards each end), as in Nitzschia.

Literature

References are given in chronological order.

Reference
Citation
Kützing F.T. 1844. Die Kieselschaligen Bacillarien oder Diatomeen. Fr. Fritsch, Nordhausen. 152 pp; 30 pls Morphology; Taxonomy; Description
Krammer K., Lange-Bertalot H. 1988. Süßwasserflora Mitteleuropas. Bacillariophyceae. 2. Teil. Bacillariophyceae, Epithemiaceae, Surirellaceae. Eds. Ettl H., Gerloff J., Heynig H., Mollenhauer D., Gustav Fischer Verlag, Stuttgart. 596 pp Morphology; Illustrations;
Lange-Bertalot H. 1993. 85 neue Taxa und über 100 weitere neu definierte Taxa ergänzend zur Süßwasserflora von Mitteleuropa Vol.2/1-4. Bibliotheca Diatomologica 27, J. Cramer, Berlin, Stuttgart. 454 pp
Lange-Bertalot H., Krammer K. 1993. Observations on Simonsenia and some small species of Denticula and Nitzschia. Nova Hedwigia, Beiheft. 106: 121-131. Morphology; Illustrations
Hamsher S.E., Graeff C.L., Stepanek J.G., Kociolek J.P. 2014. Frustular morphology and polyphyly in freshwater Denticula (Bacillariophyceae) species, and the description of Tetralunata gen. nov. (Epithemiaceae, Rhopalodiales). Plant Ecology and Evolution. 147(3): 346–365. Morphology; Biology; Ecology; Illustrations
This page should be cited as:

Mann D. G. Denticula Kützing; 1844; 43. 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=3751. [Accessed:  ].

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Record last modified: 27/12/2020