Taxon Account

Fragilaria mesolepta Rabenhorst; 1861; no. 1041; Rabenhorst 1863: 30

Synonymy

Fragilaria capucina var. mesolepta (Rabenh.) Rabenh. 1864

Key references

Tuji A., Williams D.M. 2008. Examination of the type material of Fragilaria mesolepta Rabenhorst and two similar, but distinct, taxa. Diatom Research. 23(2): 503-510.

Morphology

Size
Lenght 31.5-38.2 µm, maximum width 3.1-3.6 µm (UK population); 24.3-54.6 µm, 3.6-5 µm (Rabenhorst packet 689, Grunow Collection, Vienna, Tuji & Williams 2008); 20-60 µm, 3.5-4.5 µm (Lange-Bertalot et al. 2017).

Shape
Valves linear-lanceolate with a central constriction, so becoming panduriform, with protracted rostrate or subcapitate poles.

Symmetry
Isopolar, bilaterally symmetrical.

Striae
Indistinct, parallel, faint or appearing absent in the centre of the valve, striae of opposite sides are usually off set.

Axial area
Sternum narrow, linear.


SEM morphology
Interlinking, spatulate spines along the valve margins, to allow colony formation.

One rimoportula present in a stria on the mantle close to the valve/mantle junction near the pole.

Literature

References are given in chronological order.

Reference
Citation
Rabenhorst L.G. 1861. Die Algen Europa's. Fortsetzung der Algen Sachsens, resp. Mittel-Europa's. Decades 3-4, numbers 1021-1040. Dresden. Description; Morphology
Hoagland K.D., Rosowski J.R. 1978. Valve and band morphology of some freshwater diatoms. I. Fragilaria capucina var. mesolepta. Journal of Phycology. 14: 479-485. Morphology; Illustrations
Kociolek J.P. 2004. Annotated listing of diatom types in Rabenhorst's Die Algen Europa's 1848-1882, and a consideration of their nomenclatural status. Proceedings of the California Academy of Sciences. 55(13): 255-299. Taxonomy
Tuji A., Williams D.M. 2008. Examination of the type material of Fragilaria mesolepta Rabenhorst and two similar, but distinct, taxa. Diatom Research. 23(2): 503-510. Morphology; Type Illustration; Taxonomy;

Similar Species

Similar species not published on this website:

Fragilaria subconstricta Østrup; 1910; 192

Fragilaria tenuistriata Østrup; 1910; 193

This page should be cited as:

Williams D. M., Jüttner I. Fragilaria mesolepta Rabenhorst; 1861; no. 1041; Rabenhorst 1863: 30. 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=4439. [Accessed:  ].

Image Gallery

Record last modified: 27/12/2020