Stauroneis sonyae

Kulikovskiy, Lange-Bert., Witkowski and Dorofeyuk 2010      Category: Symmetrical biraphid

Stauroneis smithii var. incisa


Stauroneis subborealis

LM scalebar = 10 µm = 20 pixels.


Contributor: Loren Bahls - December 2011
Length Range: 118-177 µm
Width Range: 26-37 µm
Striae in 10 µm: 14-16


Valves are elliptic-lanceolate with narrow, short protracted, obtusely rounded apices. The axial area is moderately broad, about 3-4 times wider than the raphe. The stauros is very wide and distinctly expanded toward the valve margins in the shape of a bow tie. The stauros typically contains several short striae along each margin. Raphe fissures are lateral. Proximal raphe ends are strongly inflated and curved toward the secondary side. Terminal raphe fissures are hooked, the hooks opening to the secondary side. Striae are radiate throughout, becoming more radiate toward the valve apices. Areolae are round and distinct, 15-18 in 10 µm.

Original Description

Author: Kulikovskiy, Lange-Bert., Witkowski and Dorofeyuk 2010
Length Range: 120-170 µm
Width Range: 27-36 µm
Striae in 10 µm: 14-16

Original Description

Description: Differential diagnosis versus Stauroneis medioasiatica Metzeltin, Lange-Bertalot & Soninkhishig 2009. Valves lanceolate tapering to the short-protracted and obtusely rounded ends which are 6-11 µm broad. Length 120-170 (not 70-133) µm, breadth 27-36 (not 18-25) µm. Raphe lateral with reverse lateral central ends; external fissure distinctly (not slightly) curving into clearly expanded pores deflected to the secondary valve side. Axial area rather broad (neither distinctly expanded nor constricted proximally). Central area forming a broad, bow-tie-shaped fascia, in most cases with irregularly shortened marginal striae. Striae radiate throughout, 14-16 (i.e. only slightly less than 15-17) in 10 µm. Areolae in both species 15-18 in 10 µm. cf. also other larger-sized taxa mentioned in the differential diagnosis of S. medioasiatica that are altogether distinguished by another complex of characters. Stauroneis heinii Lange-Bertalot & Krammer (see above) differs mainly by its less expanded central area towards valve margins and denser spaced striae (16.5-18) in 10 µm as far as populations from Mongolia are concerned.

Original Images

Cite This Page:
Bahls, L. (2011). Stauroneis sonyae. In Diatoms of the United States. Retrieved April 23, 2018, from

Species: Stauroneis sonyae

Contributor: Loren Bahls

Reviewer: Pat Kociolek


Bahls, L. (2010). Stauroneis in the Northern Rockies: 50 species of Stauroneis sensu stricto from western Montana, northern Idaho, northeastern Washington and southwestern Alberta, including 16 species described as new. Northwest Diatoms, Volume 4. The Montana Diatom Collection, Helena, 172 pp.

Kulikovskiy, M.S., Lange-Bertalot, H., Witkowski, A., Dorofeyuk, N.I. and Genkal, S.I. (2010). Diatom assemblages from Sphagnum bogs of the world. I. Nur bog in northern Mongolia. Bibliotheca Diatomologica 55: 1-326.

Metzeltin, D., Lange-Bertalot, H. and Soninkhishig, N. (2009). Diatoms in Mongolia. Iconographia Diatomologica (H. Lange-Bertalot, ed.), Vol. 20, A. R. G. Gantner Verlag K. G., Ruggell, 691 pp.

Links & ID's

Index Nominum Algarum (INA)

California Academy of Sciences (CAS)

North American Diatom Ecological Database (NADED)


Autecology Discussion

Stauroneis sonyae was found in periphyton samples collected from five lakes, ponds, and fens in western Montana and southwestern Alberta. The pH of these waters ranges from 6.9 to 7.8 and specific conductance ranges from 67 to 1769 µS/cm.


Daphnia Pond, Flathead County, Montana (circa 1902): home of Stauroneis sonyae.

Credit/Source: Morton Elrod