Bahls 2010 Category: Symmetrical biraphid
BASIONYM: Stauroneis finlandia Bahls 2010
REPORTED AS: Stauroneis javanica (Krammer and Lange-Bertalot 1986) | Stauroneis javanica (Hustedt 1959) | Stauroneis javanica (Molder and Tynni 1973)
Contributor: Loren Bahls - November 2011
Length Range: 109-221 µm
Width Range: 24-34 µm
Striae in 10 µm: 13-15
Valves are broadly lanceolate with gradually attenuated subrostrate apices. A prominent pseudoseptum is present at each apex. The axial area is broad, about three times the width of the raphe, and becomes somewhat wider near the central area. The central area is a nearly rectangular stauros, only slightly wider at the valve margins. Raphe fissures are lateral, becoming reverse lateral and strongly curved near the large, proximal pores. Distal raphe fissures are hooked toward the secondary side. Striae are radiate throughout. Areolae are coarse and number 12-15 in 10 µm.
Basionym: Stauroneis finlandia
Author: Bahls 2010
Length Range: 110-221 µm
Width Range: 25-34 µm
Striae in 10 µm: 13-15
Valves broadly lanceolate with gradually attenuated subrostrate ends. Length 110-221 µm, width 25-34 µm. A prominent pseudoseptum is present at each apex. Axial area broad, expanding in deltoid fashion into the central area. Central area a nearly rectangular fascia, only slightly wider at the valve margins. Raphe fissures lateral, becoming reverse lateral and strongly curved near the large central pores. Distal raphe fissures hooked toward the secondary side. Striae radiate, 13-15 in 10 µm. Striae puncta 12-15 in 10 µm. For measurements, n = 24 valves.
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.
Hustedt, F. (1959). Die Kieselalgen Deutschlands, Osterreichs und der Schweiz, 2. Teil. In: Kryptogamen-Flora von Deutschlands, Osterreichs und der Schweiz, (Dr. L. Rabenhorst, ed.), Band VII(2). Reprint 1977, Otto Koeltz Science Publishers, Koenigstein, 845 pp.
Krammer, K. and Lange-Bertalot, H. (1986). Bacillariophyceae. 1. Teil: Naviculaceae. In: Ettl, H., J. Gerloff, H. Heynig and D. Mollenhauer (eds.) Susswasserflora von Mitteleuropa, Band 2/1. Gustav Fisher Verlag, Jena. 876 pp.
Lange-Bertalot, H. and Genkal, S.I. (1999). Diatoms from Siberia I. Islands in the Arctic Ocean (Yugorsky-Shar Strait). Iconographia Diatomologica 6: 1-292.
Molder, K. and Tynni, R. (1973). Uber Finnlands rezente und subfossile diatomeen VII. Bulletin of the Geological Society of Finland 45: 159-179.
Van de Vijver, B., Beyens, L. and Lange-Bertalot, H. (2004). The genus Stauroneis in Arctic and Antarctic Regions. Bibliotheca Diatomologica 50, 312 pp.
In the Northern Rockies, Stauroneis finlandia has been found in three small ponds and fens in western Montana. Measured pH at the type locality (Johns Fen, Glacier National Park) was 6.0 and specific conductance was 58 µS/cm.
Starvation Ridge Pond, Glacier National Park, Montana: home of Stauroneis finlandia.
Credit/Source: Billy Schweiger, National Park Service