Taxon Account

Actinocyclus Ehrenberg; 1837; 61

Key references

Boyer C. S. 1927. Synopsis of North American Diatomaceae. 78. Proceedings of The Acadamy of Natural Sciences of Philadelphia. 228 pp

Watkins T.P., Fryxell G.A. 1986. Generic characterization of Actinocyclus: consideration in light of three new species. Diatom Research. 1(2): 291-312.

Round F.E., Crawford R.M., Mann D.G. 1990. The Diatoms. Biology & Morphology of the Genera. Cambridge University Press, Cambridge. 747 pp

Morphology

Cells disc-like or in the form of a short barrel, with radiating striae arranged in sectors (fascicles). Valve face sometimes flat, but often concentrically undulate, so that in LM the whole of the valve face cannot all be in focus at the same time. Mantle usually clearly differentiated from the valve face and possessing more densely spaced striae, sometimes bearing a shallow ridge at the junction with the valve face. Areolae large, closely packed, and chambered (SEM). A ring of widely and equally spaced rimoportulae (labiate processes) is present near the periphery of the valve face or on the mantle, appearing in LM as a series of dark spots or flared structures. Also present near the periphery of the valve face or on the mantle is a 'pseudonodulus': a small area in which the valve is differently structured and thinner. This can be extremely difficult or impossible to detect in freshwater species like A. normanii, but is often obvious in large-celled marine species, making them easy to separate in LM from otherwise rather similar species of Coscinodiscus.

Literature

References are given in chronological order.

Reference
Citation
Ehrenberg C.G. 1837. Nachricht des Hrn Agassiz in Neuchatel über den ebenfalls aus mikroskopichen Kiesel-Organismen gebildeten Polirschiefer von Oran in Afrika. 1837. Bericht über die zur Bekanntmachung geeigneten Verhandlungen der Königlich-Preussischen Akademie der Wissenschaften zu Berlin. 59-61 pp Description
Boyer C. S. 1927. Synopsis of North American Diatomaceae. 78. Proceedings of The Acadamy of Natural Sciences of Philadelphia. 228 pp Morphology; Taxonomy;
Watkins T.P., Fryxell G.A. 1986. Generic characterization of Actinocyclus: consideration in light of three new species. Diatom Research. 1(2): 291-312. Morphology; Illustrations; Taxonomy
Round F.E., Crawford R.M., Mann D.G. 1990. The Diatoms. Biology & Morphology of the Genera. Cambridge University Press, Cambridge. 747 pp Morphology; Illustrations;
This page should be cited as:

Mann D. G. Actinocyclus Ehrenberg; 1837; 61. In: Jüttner I., Bennion H., Carter C., Cox E.J., Ector L., Flower R., Jones V., Kelly M.G., Mann D.G., Sayer C., Turner J. A., 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=4196. [Accessed:  ].

Image Gallery

Record last modified: 27/12/2020