Lange-Bertalot 1985 Category: Symmetrical biraphid
BASIONYM: Navicula margalithii Lange-Bertalot 1985
Contributor: Loren Bahls - January 2016
Length Range: 35.0-68.0 µm
Width Range: 6.5-9.0 µm
Striae in 10 µm: 12-13
Valves are linear-lanceolate with wedge-shaped ends.The raphe is straight and filiform. The axial area is very narrow and linear. The central area is small and asymmetric. Proximal raphe ends are tear-shaped and straight. Striae are radiate and somewhat sinuous at the valve center, becoming parallel and straight, and then convergent near the apices. Central striae in larger specimens are sometimes alternately long and short. Areolae number about 32 in 10 µm.
This taxon is very similar to Navicula recens and differs mainly in valve size and salinity tolerance. It should not be ruled out that they are conspecific, with the larger size specimens that we call N. margalithii simply a morphological manifestation of the more electrolyte-rich waters in which they are found.
Basionym: Navicula margalithii
Author: Lange-Bertalot 1985
Length Range: 30-70 µm
Width Range: 8-10 µm
Striae in 10 µm: 9-12
Krammer, K. and Lange-Bertalot, H. (1985). Naviculaceae Neue und wenig bekannte Taxa, neue Kombinationen und Synonyme sowie Bemerkungen zu einigen Gattungen. Bibliotheca Diatomologica 9:5-230, 43 pls.
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. (2001). Navicula sensu stricto, 10 genera separated from Navicula sensu lato, Frustulia. Diatoms of Europe 2: 1-526.
This taxon prefers electrolyte-rich waters. The specimens on this page are from a stream in Wyoming that has a specific conductance of 18,100 µS/cm and a chloride content of 60 mg/L. Common diatom associates at this site include Haslea spicula, Mastogloia pumila, and Tryblionella compressa. Lange-Bertalot (2001) reports N. margalithii from saline, electrolyte-rich springs in the Negev Desert of Israel and Tunisia. In contrast, Navicula tripunctata and N. recens prefer fresh to brackish waters.
Stockade Beaver Creek below Salt Creek, Weston County, Wyoming: home of Navicula margalithii.
Credit/Source: State of Wyoming DEQ