Contributor: Loren Bahls - April 2016
Length Range: 16-42 µm
Width Range: 6.1-8.8 (initial valve 10.5) µm
Striae in 10 µm: 12-14 dorsal, 14-15 ventral at valve center, up to 16 at the apices
Valves are dorsiventral and lanceolate, with rounded apices. The dorsal margin is strongly arched; the ventral margin is convex, sometimes with a slightly tumid center. The central area is a somewhat wider continuation of the axial area. The raphe is distinctly lateral. The raphe is filiform to weakly reverse-lateral and ventrally deflected. Proximal raphe ends terminate in slightly inflated pores. Distal raphe fissures are deflected dorsally. Striae are radiate, becoming more strongly radiate near the apices. Areolae are distinct in LM and number 24-28 in 10 µm. A stigma is absent.
Author: Krasske 1923
Length Range: 20 µm
Width Range: 7 µm
Striae in 10 µm: 13
Krammer, K. (2002). The genus Cymbella. Diatoms of Europe. Diatoms of the European Inland Waters and Comparable Habitats 3: 1-584.
Krasske, G. (1923). Die Diatomeen des Casseler Beckens und seiner Randgebirge, nebst einigen wichtigen funden aus Niederhessen. Botanisches Archiv. Konigsberg 3(4):185-209.
Lange-Bertalot, H., Kulbs, K., Lauser, T., Norpel-Schempp, M. and Willmann, M. (1996). Diatom Taxa introduced by Georg Krasske: Documentation and Revision. Iconographia Diatomologica (H. Lange-Bertalot, ed.), Vol. 3, Koeltz Scientific Books, Konigstein, 358 pp.
Patrick, R.M. and Reimer, C.W. (1975). The Diatoms of the United States, exclusive of Alaska and Hawaii, V. 2. Monographs of the Academy of Natural Sciences of Philadelphia 13.
The images of C. hustedtii shown on this web page are from the Redwater River, a prairie stream in Montana (photo below). Measured pH values in the Redwater River range from 7.76 to 8.40 and specific conductance values range from 944 to 4652 µS/cm. Krammer (2002) reports this species as widespread in the temperate zone in oligotrophic waters with low to average electrolyte content.
Redwater River, McCone County, Montana: home of Cymbella hustedtii
Credit/Source: Loren Bahls