Navicula schweigeri
Bahls 2012 Category: Symmetrical biraphid
BASIONYM: Navicula schweigeri Bahls 2012
LM scalebar = 10 µm = 80 pixels.
Observations
Contributor: Loren Bahls - March 2012
Length Range: 39-49 µm
Width Range: 7.5-8.6 µm
Striae in 10 µm: 12-14
Description
Valves are lanceolate with short, rostrate apices. Raphe branches are filiform. Proximal raphe ends are straight or deflected slightly to one side. Distal raphe fissures are hooked to the secondary side. The axial area is very narrow. The central area is small and lanceolate and bordered by irregularly shortened striae, often alternating long and short. Striae are radiate and become strongly convergent near the apices. Areolae number 32–36 in 10 μm and are barely visible in LM.
Original Description
Basionym: Navicula schweigeri
Author: Bahls 2012
Length Range: 39-49 µm
Width Range: 7.5-8.6 µm
Striae in 10 µm: 12-14
Original Description
Valves lanceolate with short protracted and obtusely rounded ends, 39 – 49 μm long, 7.5 – 8.6 μm wide. Raphe filiform, proximal endings straight or deflected slightly to one side, distal raphe fissures hooked to the secondary side. Axial area very narrow. Central area small and lanceolate, bordered by irregularly shortened striae. Striae radiate, becoming strongly convergent toward the ends, 12 –14 in 10 μm, lineolae 32 – 36 in 10 μm, barely visible in LM. For measurements, n = 22 valves.
Original Images
Cite This Page:
Bahls, L. (2012). Navicula schweigeri. In Diatoms of the United States. Retrieved May 21, 2013, from http://westerndiatoms.colorado.edu/taxa/species/navicula_schweigeri
Species: Navicula schweigeri
Contributor: Loren Bahls
Reviewer: Mark Edlund
Image Credit: Loren Bahls
- Valves 39-49 μm long, 7.5-8.6 μm wide
- Apices short, rostrate
- Central area small, lanceolate
- Central striae irregularly shortened
Navicula schweigeri has lanceolate valves that measure 39-49 μm long by 7.5-8.6 μm wide. Apices are short and rostrate. The central area is small, lanceolate and bordered by irregularly shortened striae.
Compare
Navicula schweigeri is easily distinguished from N. capitatoradiata by its larger size and wider, rostrate apices. Although similar morphologically, N. arkona is decidedly larger than N. schweigeri. Navicula schweigeri may be distinguished from N. subalpina and N. krammerae by its wider valves and more broadly rounded apices.
Navicula capitatoradiata
Navicula arkona
Lange-Bertalot & Witkowski
Navicula krammerae
Lange-Bertalot
Navicula subalpina
Reichardt
Citations
Bahls, L.L. (2012). Seven new species in Navicula sensu stricto from the Northern Great Plains and Northern Rocky Mountains. Nova Hedwigia, Beiheft 141: 19–38.
Links & ID's
Index Nominum Algarum (INA)
California Academy of Sciences (CAS)
North American Diatom Ecological Database (NADED)
NADED ID:
Autecology Discussion
Navicula schweigeri has been found in 18 lakes and streams in western Montana and southern Alberta, where it is present in low numbers. This taxon prefers waters with neutral to somewhat alkaline pH (range = 7.1-8.7) and low to moderate levels of electrolytes (range = 90-201 μS/cm).
Images
Lake McDonald in winter, Glacier National Park, Montana. Lake McDonald is home to Navicula schweigeri.
Credit/Source: National Park Service webcam photo.