Nitzschia clausii
Hantzsch 1860 Category: Nitzschioid
BASIONYM: Nitzschia clausii Hantzsch 1860
SYNONYM(S): Nitzschia sigma var. clausii (Hantzsch) Grunow
LM scalebar = 10 µm = 80 pixels.
Observations
Contributor: Pat Kociolek - September 2011
Length Range: 20.0-68.0 µm
Width Range: 3.0-5.0 µm
Striae in 10 µm:
Description
In girdle view, the frustules are distinctly sigmoid. Valves are linear and slightly concave at the center. The apices are distinctly rounded, capitate or rostrate and bent to form a sigmoid valve shape. The striae are very fine. The keeled raphe is distinct, with robust fibulae. Fibula density is 10-13 in 10 µm.
Krammer and Lange-Bertalot (1988, Plate 19, Figs 1-6A) illustrate longer specimens of this species (e.g. Fig. 5) that are narrower than the shorter specimens (e.g. Fig. 1), suggesting that more than one taxon might be included in their concept of the species.
Original Description
Basionym: Nitzschia clausii
Author: Hantzsch 1860
Length Range: µm
Striae in 10 µm:
Original Description
Original Images
Cite This Page:
Kociolek, P. (2011). Nitzschia clausii. In Diatoms of the United States. Retrieved May 25, 2013, from http://westerndiatoms.colorado.edu/taxa/species/nitzschia_clausii
Species: Nitzschia clausii
Contributor: Pat Kociolek
Reviewer: Loren Bahls
Image Credit: Pat Kociolek
- Valve apices curved in opposite directions
- Striae very fine
- Valve slightly concave at center
The valve apices are curved in opposite directions. The striae are very fine and difficult to resolve in the LM. At the center, the valve is slightly concave.
Compare
Nitzschia clausii is comparatively narrower than N. brevissima and has finer striae than both N. filiformis and N. sigma. The valves of N. clausii are more sigmoid in shape and have narrower, more constricted apices than N. filiformis. Nitzschia clausii has a curved keel at the valve center, while that of N. sigma is straight at the valve center. N. clausii is narrower and has more narrowly rounded apices than N. scalpelliformis. Nitzschia clausii has apices that are more constricted than those of N. nana.
Nitzschia brevissima
Nitzschia filiformis
Nitzschia sigma
Nitzschia scalpelliformis
Grunow
Nitzschia nana
Grunow in Van Heurck
Citations
Hantzsch, C. A. (1860). Neue Bacillarien: Nitzschia vivax var. elongata, Cymatopleura nobilis. Hedwigia 2(7):40, pl. 6.
Krammer, K. and Lange-Bertalot, H. (1988). Bacillariophyceae. 2. Teil: Bacillariaceae, Epithemiaceae, Surirellaceae. In: Ettl, H., J. Gerloff, H. Heynig and D. Mollenhauer (eds.) Susswasserflora von Mitteleuropa, Band 2/2. Gustav Fisher Verlag, Jena.
Rabenhorst, L. (1860). Die Algen Sachsens resp. Mittel-Europa’s. Decas 95-96. no. 943-953 etc. .
Links & ID's
Index Nominum Algarum (INA)
California Academy of Sciences (CAS)
North American Diatom Ecological Database (NADED)
NADED ID: 48137