Eunotia bactriana

Ehrenb. 1854      Category: Eunotioid

Eunotia areniverma


Eunotia bidens

LM scalebar = 10 µm = 40 pixels.


Contributor: Ian Bishop - June 2016
Length Range: 31-38 µm
Width Range: 5.0-6.4 µm
Striae in 10 µm: 14-16 at mid-valve; up to 18 at valve ends


Valve outline is complex. The dorsal margin is convex and contains two prominent, pointed, widely-set undulations. Between these undulations, the dorsal margin may become less uniformly convex in smaller valves. The ventral margin is concave but becomes more linear in smaller specimens. The ventral margin also has subtle undulations where the valve is widest. Apices are capitate and dorsally recurved. Terminal raphe ends are visible near the apices. Striae are evenly spaced through most of the valve, becoming slightly denser at the apices. Areolae are dense and only barely visible with ideal illumination in LM.

Original Description

Author: Ehrenb. 1854
Length Range: µm
Striae in 10 µm:

Original Description

Original Images

Cite This Page:
Bishop, I. (2016). Eunotia bactriana. In Diatoms of the United States. Retrieved April 25, 2018, from

Species: Eunotia bactriana

Contributor: Ian Bishop

Reviewer: Sarah Spaulding


Ehrenberg, C.G. (1854). Mikrogeologie. Einundvierzig Tafeln mit über viertausend grossentheils colorirten Figuren, Gezeichnet vom Verfasser. Voss, Leipzig., Pl. 5, II, fig. 23 (iconotype).

Lebednik, G. K., and del Moral, R. (1976). Vegetation surrounding Kings Lake Bog, Washington. Madrono 23 (7): 386-400.

Pavlov, A. and Levkov, Z. (2013). Diversity and distribution of taxa in the genus Eunotia Ehrenberg (Bacillariophyta) in Macedonia. Phytotaxa 86: 1-117. 10.11646/phytotaxa.86.1.1

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Eunotia bactriana CAS

North American Diatom Ecological Database (NADED)

NADED ID: 33003

Autecology Discussion

Lange-Bertalot et al. (2011) suggest that this taxon is most often found in oligo- to dystrophic, moderately acid waters. The population imaged above was collected at Kings Lake Bog, a small, well-protected, oligotrophic, lowland sphagnum bog in the Puget Trough (Lebednik and del Moral 1976).