Navicula schmassmannii
Hustedt 1943 Category: Symmetrical biraphid
BASIONYM: Navicula schmassmanni Hustedt 1943
GENUS CONSIDERED: Chamaepinnularia
LM scalebar = 10 µm = 80 pixels.
Observations
Contributor: Megan Otu | Sarah Spaulding - March 2011
Length Range: 7.4-8.4 µm
Width Range: 2.4-4.0 µm
Striae in 10 µm: 30-43
Description
Valves are linear elliptical with convex margins and capitate, rostrate or blunt apices. Specimens within a population may be irregular (asymmetrical) and are often variable in the shape of the apices. In general, the axial area is narrow near the apices, becoming more broad near the central area. The central area is lanceolate, with a thickened and distinct central nodule. The raphe is filiform and straight, with slightly expanded external proximal raphe ends. Internally, the helictoglossae are small and indistinct. The striae are parallel to slightly radiate in the central valve. The striae are variable in the center valve; some stria may be shorter or curved in the center of the valve. Striae are composed of a single, elongate areola on the valve face. A smaller areola is positioned on the valve mantle. Internally, the proximal raphe has short, deflected ends.
Note that this species is currently considered within Navicula, but it would be more appropriately treated within Chamaepinnularia. A nomenclatural transfer, however, has not yet been published.
Original Description
Basionym: Navicula schmassmanni
Author: Hustedt 1943
Length Range: 6-10 µm
Width Range: 2.5-3 µm
Striae in 10 µm: 24-30 in the center valve, 36-40 at the ends
Original Description
Navicula Schmassmanni Hust., in A.S. Atl., T. 400, F. 48 bis 52. Im Davoser Gebiet ziemlich verbreitet: Kleiner Flüelasee, Schwarzsee und in dessen Abfluss, oberer und unterer Grialetschsee. Wurde 1934 (l.c.) als neue Art aus diesem Material veröffentlicht:
Schalen im Umriss linear-elliptisch mit stark konvexen Rändern und breiten, kopfig abgeschnürten Enden, 6-10 µ lang, 2,5-3 µ breit. Raphe gerade, mit zeimlich entfernt gestellten Zentralporen. Axialarea und Zentralarea einen schmal lanzettlichen Raum einnehmend, ohne besonders abgesetzte Zentralarea. Transapikalstreifen durchweg leicht radial, im mittleren Teil der Schale 24-30 in 10 µ, gegen die Enden allmählich enger werdend, vor der Polen 36-40 in 10 µ. (Abb. 36, 37)
Original Images
Cite This Page:
Otu, M., and Spaulding, S. (2011). Navicula schmassmannii. In Diatoms of the United States. Retrieved May 23, 2013, from http://westerndiatoms.colorado.edu/taxa/species/Navicula_schmassmannii
Species: Navicula schmassmannii
Contributor: Megan Otu | Sarah Spaulding
Reviewer: Pat Kociolek
Image Credit: Megan Otu
- Valves small, irregularly shaped
- Apices capitate, rostrate or blunt
- Each stria a single, elongate areola
Valves are linear elliptical with convex margins and capitate, rostrate or blunt apices. Specimens within a population may be irregular (asymmetrical) and are often variable in the shape of the apices. The axial area is narrow near the apices, becoming more broad near the central area. The central nodule is thickened and distinct. Each stria is composed of a single, elongate areola.
Compare
Navicula schmassmannii is similar in shape to N. medioconvexa, but N. schmassmannii is smaller, the central area is less distinct, and each stria is a single, elongate areola rather than uniseriate. Navicula schadei is similar in valve outline, but the central striae are radiate.
Navicula medioconvexa
Hustedt
Navicula schadei
Krasske
Citations
Hustedt, F. (1943). Die Diatomeenflora einiger Hochgebirgsseen der Landschaft Davos in den schweizer Alpen. Internationale Revue der gesamten Hydrobiologie und Hydrographie 43:124-197, 225-280.
Šporka, F., Štefkov, E., Bitušík, P., Thompson, A.R., Agustí-Panareda, A., Appleby, P.G., Grytnes, J.A., Kamenik, C., Krno, I., Lami, A., Rose, N. and Shilland, N.E. (2002). The paleolimnological analysis of sediments from high mountain lake Nizné Terianske pleso in the High Tatras (Slovakia). Journal of Paleolimnology 28: 95-109. 10.1023/A:1020376003123
Links & ID's
Index Nominum Algarum (INA)
California Academy of Sciences (CAS)
North American Diatom Ecological Database (NADED)
NADED ID: