Amphora calumetica

(B.W.Thomas ex Wolle) Perag. 1897      Category: Asymmetrical biraphid
BASIONYM: Amphiprora calumetica B.W.Thomas ex Wolle 1890

Amphora bicapitata


Amphora copulata

LM scalebar = 10 µm = 40 pixels.


Contributor: David R.L. Burge | Mark Edlund - February 2017
Length Range: 53-66 µm
Striae in 10 µm: 13-14


Valves are semi-lanceolate, with a convex dorsal margin. A large siliceous crest lies on the centreal dorsal face/mantle junction. The crest is narrow near the base, and expands distal to the valve. The ventral side is nearly straight or slightly concave, with a slightly tumid central margin. Valve apices are rounded and ventrally deflexed. The raphe is filiform and arcuate, with dorsally deflected proximal ends. The central area is triangular with a narrow ventral side, which may extend to the ventral margin in some specimens. Striae are parallel at the valve center, becoming radiate near the apices, occurring 13-14 in 10 µm throughout. The striae are uniseriate and composed of round areolae, occurring 18-20 in 10 µm. The dorsal mantle is curved and ornamented with stria and areola of lower density (ca. 11 in 10 µm) compared to the stria and areola density of the valve face.

Original Description

Basionym: Amphiprora calumetica
Author: B.W.Thomas ex Wolle 1890
Length Range: µm
Striae in 10 µm:

Original Description

Amphiprora CALUMETICA, List of diatoms of Lake Michigan, B.W. Thomas. Chicago.

Original Images

Cite This Page:
Burge, D., and Edlund, M. (2017). Amphora calumetica. In Diatoms of the United States. Retrieved April 26, 2018, from

Species: Amphora calumetica

Contributor: David R.L. Burge | Mark Edlund

Reviewer: Sarah Spaulding


Edlund, M.B. and Stoermer, E.F. (1999). Taxonomy and morphology of Amphora calumetica (B.W. Thomas ex Wolle) Perag., an epipsammic diatoma from post-pleistocene large lakes. In: Mayama, Idei, and Koizumi (eds.) 14th International Diatom Symposium 1996, Koeltz Scientific Books, Koenigstein. pp. 63-74.

Levkov, Z. (2009). Amphora sensu lato. In Diatoms of Europe, Volume 5. (H. Lange-Bertalot, ed). A.R.G. Gantner Verlag K.G. 916pp.

Stoermer, E.F. and Yang, J.J. (1971). Contributions to the diatom flora of Laurentian Great Lakes. I. New and little known species of Amphora (Bacillariophyta, Pennatibacilariophyceae). Phycologia 10: 397-409.

Stoermer, E. F. and Yang, J. J. (1969). Plankton diatom assemblages in Lake Michigan. Univ. Michigan, Great Lakes Res. Div. Spec. Rep. No. 47, 168 pp.

Thomas, B.W. and Chase, H.H. (1886). Diatomaceae of Lake Michigan as collected during the last 16 years from the water supply of the City of Chicago. Notarisia 2: 328-330.

Wolle, F. (1890). Diatomaceae of North America. The Commenius Press, Bethlehem, Pennsylvania. 47 pp., 112 pl.

Links & ID's

Index Nominum Algarum (INA)

Transfer INA
Original INA

California Academy of Sciences (CAS)

Amphora calumetica CAS

North American Diatom Ecological Database (NADED)


Autecology Discussion

Amphora calumetica has been reported as a rare taxon in Lake Michigan plankton communities (Stoermer and Yang 1969, 1971, Stoermer 1980, Edlund and Stoermer 1999). It is more common in in epipsammic communities of Lake Michigan and Lake Huron, with specimens illustrated here from nearshore Lake Superior. It has also been reported from a large oligotrophic lake in Mongolia (Levkov 2009).

Chloroplasts of A. calumetica are “H-shaped” with a strongly constricted central bridge that connects two long plastid arms that lie parallel to the dorsal margin of the each valve face. Living cells contain two prominent volutin granules located equidistant from the valve center to the apices.


Living cell, ventral view of A. calumetica. Epipsammon, St. Joseph, Lake Michigan.

Credit/Source: Image by Mark Edlund