Taxon Account

Semiorbis hemicyclus (Ehrenberg) R.M.Patrick in Patrick & Reimer; 1966; 163

Key references

Patrick R., Reimer C.W. 1966. The Diatoms of the United States. Exclusive of Alaska and Hawaii. Volume 1. Fragilariaceae, Eunotiaceae, Achnanthaceae, Naviculaceae. Monographs of the Academy of Natural Sciences of Philadelphia 13. 688 pp; 64 pls.

Kobayasi H., Nagumo T. 1978. On the fine structure of the pennate diatom Semiorbis hemicyclus (Ehr.) Patr. The Japanese Journal of Phycology. 26: 171-175.

Reid G., Williams D.M. 2010. Notes on the genus Semiorbis Patrick with a description of a new species. Diatom Research. 25(2): 355-365.

Morphology

Size
22-46 µm long, 3.8-5 µm wide (Reid & Williams 2010).

Shape
Valves strongly lunate.

Symmetry
Dorsiventral, isopolar.

Striae
Striae located between silica ridges, not discernible in LM.

Raphe
A short, simple slit at each pole, located near the valve margin, terminal fissures curving onto valve face near the poles.


SEM morphology
Striae uniseriate in ventral part of the valve, mostly biseriate in dorsal part of the valve, separated by a central hyaline area which extends over the length of the valve.

Literature

References are given in chronological order.

Reference
Citation
Ehrenberg C.G. 1840. Charakteristik von 274 neue Arten von Infusorien. Bericht über die zur Bekanntmachung geeigneten Verhandlungen der Königlichen Preussischen Akademie der Wissenschaften zu Berlin. 196-219. Description
Ehrenberg C.G. 1854. Mikrogeologie. Das Erden und Felsen schaffende Wirken des unsichtbar kleinen selbstständigen Lebens auf der Erde. Leopold Voss, Leipzig. 374 pp; 40 pls Illustrations
Patrick R., Reimer C.W. 1966. The Diatoms of the United States. Exclusive of Alaska and Hawaii. Volume 1. Fragilariaceae, Eunotiaceae, Achnanthaceae, Naviculaceae. Monographs of the Academy of Natural Sciences of Philadelphia 13. 688 pp; 64 pls. Morphology; Taxonomy; Illustrations; Ecology
Moss M.O., Gibbs G., Gray V., Ross R. 1978. The presence of a raphe in Semiorbis hemicyclus (Ehrenb.) Patr. Bacillaria. 1: 137-150. Morphology; Illustrations
Kobayasi H., Nagumo T. 1978. On the fine structure of the pennate diatom Semiorbis hemicyclus (Ehr.) Patr. The Japanese Journal of Phycology. 26: 171-175. Morphology; Illustrations;
Morrow A.C., Deason T.R., Clayton D. 1981. A new species of the diatom genus Eunotia. Journal of Phycology. 17: 265-270. Morphology; Illustrations
Davis R.B., Norton S.A., Hess C.T., Brakke D.F. 1983. Paleolimnological reconstruction of the effects of atmospheric deposition of acids and heavy metals on the chemistry and biology of lakes in New England and Norway. Hydrobiologia. 103: 113-123. Ecology
Dixit S.S., Dickman M.D. 1986. Correlation of surface sediment diatoms with the present lake water pH in 28 Algoma lakes, Ontario, Canada. Hydrobiologia. 131: 133-143. Ecology
Stabell B. 1993. A pre-industrial acidification event shown by diatom analysis of a recently acidified lake in southern Norway. Diatom Research. 8(1): 145-158. Ecology
Ek A.S., Renberg I. 2001. Heavy metal pollution and lake acidity changes caused by one thousand years of copper mining at Falun, central Sweden. Journal of Paleolimnology. 26: 89-107. Ecology
Williams D.M., Reid G. 2005. Amphorotia nov. gen., a new genus in the family Eunotiaceae (Bacillariophyceae), based on Eunotia clevei Grunow in Cleve et Grunow. A.R.G. Gantner Verlag K.G., Ruggell. 153 pp Morphology
Siver P.A., Hamilton P.B., Stachura-Suchoples K., Kociolek J.P. 2005. Diatoms of North America: The Freshwater Flora of Cape Cod, Massachusetts, U.S.A.. Ruggell, A.R.G. Gantner Verlag. 463 pp Morphology; Illustrations
Metzeltin D., Lange-Bertalot H. 2007. Tropical diatoms of South America II. Special remarks on biogeography disjunction. Iconographia Diatomologica, Vol. 18., Annotated Diatom Micrographs. Diversity-Taxonomy-Biogeography. H. Lange-Bertalot (ed.), A.R.G. Gantner Verlag K.G. 877 pp Illustrations; Morphology
Reid G., Williams D.M. 2010. Notes on the genus Semiorbis Patrick with a description of a new species. Diatom Research. 25(2): 355-365. Type Illustration; Morphology; Taxonomy;
Tanaka H., Kawanobe K., Mitsuhashi F., Nagumo T. 2018. Diatoms from district of Lake Oze, boundary of Gunma and Fukushima Prefectures. The Nippon Dental University. 47(3): 7-23. Morphology; Illustrations
Edlund M.B., Burge D.R.L., Andresen N.A., Vandermeulen D.D., Stone J.R., Van de Vijver B. 2021. The genus Semiorbis (Eunotiaceae, Bacillariophyta) in North America. Diatom Research DOI: 10.1080/0269249X.2021.1875053. Morphology; Taxonomy; Illustrations
This page should be cited as:

Jones V., Jüttner I., Williams D. M., Ector L. Semiorbis hemicyclus (Ehrenberg) R.M.Patrick in Patrick & Reimer; 1966; 163. 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=4655. [Accessed:  ].

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Record last modified: 09/02/2021