(Hustedt) Lange-Bertalot and Metzeltin 1996 Category: Symmetrical biraphid
BASIONYM: Navicula abiskoensis Hustedt 1942
REPORTED AS: Navicula abiskoensis (Krammer and Lange-Bertalot 1986) | Navicula kincaidii (Sovereign 1963)
Contributor: Loren Bahls - January 2014
Length Range: 33.3-46.0 µm
Width Range: 8.4-11.1 µm
Striae in 10 µm: 10-12
Valves are linear, with parallel or weakly concave margins. Valve margins may be triundulate in the largest specimens. Apices are rostrate to sub-capitate. The axial area is very narrow and widens slightly as it approaches a transversely rectangular central area. The raphe is weakly lateral and somewhat sinuous. Proximal raphe ends are inflated and bent to one side. Distal raphe ends are hooked towards the opposite side of the valve. Striae are strongly curved and radiate except at the very ends, where they are straight and parallel. Areolae in the striae number about 26-30 in 10 µm.
Basionym: Navicula abiskoensis
Author: Hustedt 1942
Length Range: µm
Striae in 10 µm:
Hustedt, F. (1942). Diatomeen aus der Umgebung von Abisko in Schwedisch-Lappland. Archiv für Hydrobiologie, Vol: 39, Issue: 1, 87-174 .
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.
Metzeltin, D. and Witkowski, A. (1996). Diatomeen der Baren-Insel Susswasser und marine Arten. In: Iconographia Diatomologica (H. Lange-Bertalot, ed.), Vol. 4, Koeltz Scientific Books, Konigstein, 287 pp.
Simonsen, R. (1987). Atlas and Catalogue of the Diatom Types of Friedrich Hustedt. J. Cramer, Berlin & Stuttgart 1: 525 pp.
Placoneis abiskoensis is widely distributed across the Northern Great Plains and Northern Rocky Mountains in streams, lakes, ponds, pools, and wetlands. It is rarely found in large numbers. The species was described from material collected in Swedish Lapland at 68 degrees north latitude (Hustedt 1942) and also reported from Bear Island in Arctic Norway (Metzeltin & Witkowski 1996) and from many other Arctic and Subarctic locations.
Pool on trail near Kintla Lake, Glacier National Park, Montana: home of Placoneis abiskoensis.
Credit/Source: Mike Pasichnyk