Stauroneis agrestis
Petersen 1915 Category: Symmetrical biraphid
BASIONYM: Stauroneis agrestis Petersen 1915
LM scalebar = 10 µm = 80 pixels.
Observations
Contributor: Loren Bahls - May 2012
Length Range: 23-27 µm
Width Range: 4.5-5.5 µm
Striae in 10 µm: about 40
Description
Valves are linear with slightly convex margins and capitate apices. The axial area is linear and very narrow, widening slightly near the central area. The central area is a broad stauros shaped like a bow tie. The raphe is filiform and straight, with slightly expanded proximal ends. Striae are slightly curved and strongly radiate. Areolae are difficult to resolve in LM and number near 40 in 10 µm.
Original Description
Basionym: Stauroneis agrestis
Author: Petersen 1915
Length Range: µm
Striae in 10 µm:
Original Description
Original Images
Cite This Page:
Bahls, L. (2012). Stauroneis agrestis. In Diatoms of the United States. Retrieved July 23, 2014, from http://westerndiatoms.colorado.edu/taxa/species/stauroneis_agrestis
Species: Stauroneis agrestis
Contributor: Loren Bahls
Reviewer: Rex Lowe
Image Credit: Loren Bahls
- Valves linear
- Apices capitate
- Stauros broad, bow tie shaped
- Striae strongly radiate
- Proximal raphe ends straight
Stauroneis agrestis has linear valves 23-27 µm long with capitate apices. Proximal raphe ends are straight. The stauros is broad and shaped like a bow tie. Striae are strongly radiate and number near 40 in 10 µm.
Compare
Stauroneis kriegeri, another very small Stauroneis, has a nearly rectangular stauros and less strongly radiate striae. Stauroneis pseudagrestis is larger with more lanceolate valves, lower stria density and proximal raphe ends that are bent in the same direction.
Stauroneis kriegeri
Stauroneis pseudagrestis
Citations
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.
Petersen, J.B. (1915). Studier over danske aerophile alger. Mem. Acad. R. Sci. Lett. Danmark, 7. Ser. 12: 269-380.
Van de Vijver, B., Beyens, L. and Lange-Bertalot, H. (2004). The genus Stauroneis in Arctic and Antarctic Regions. Bibliotheca Diatomologica 50, 312 pp.
Werum, M. and Lange-Bertalot, H. (2004). Diatoms in springs, from Central Europe and elsewhere under the influence of hydrogeology and anthropogenic impages. Iconographia Diatomologica 13: 1-417.
Links & ID's
Index Nominum Algarum (INA)
California Academy of Sciences (CAS)
North American Diatom Ecological Database (NADED)
NADED ID: 62032
Autecology Discussion
Stauroneis agrestis has been recorded from small lakes, ponds and streams in the northern Rocky Mountains where mean pH is 6.6 and mean conductance is 9 µS/cm. Van de Vijver et al. (2004) report S. agrestis as an aerophile that is widespread in the Arctic. Werum and Lange-Bertalot (2004) report it from springs in Germany and the central Alps.
Images
Atlantic Pond, Atlantic Creek drainage, Glacier National Park, MT: home of Stauroneis agrestis.
Credit/Source: Loren Bahls