Cymbopleura subaequalis
(Grunow) Krammer 2003 Category: Asymmetrical biraphid
BASIONYM: Cymbella subaequalis Grunow in Van Heurck 1880
REPORTED AS: Cymbella subaequalis (Patrick and Reimer 1975, p. 24, plate 3, figs. 13-14)
LM scalebar = 10 µm = 80 pixels.
Observations
Contributor: Loren Bahls - August 2012
Length Range: 23-47 µm
Width Range: 7.1-10.8 µm
Striae in 10 µm: 12-16 at the valve center, 16-20 near the ends
Description
Valves are lanceolate to elliptic-lanceolate and somewhat dorsiventral. The dorsal and ventral margins are arched and taper to obtusely rounded, subtly protracted apices. The axial area is narrow and widens gradually from the apices toward the central area. The central area is small and irregular, barely wider than the axial area. The raphe is lateral and narrows toward the proximal and distal ends. Proximal raphe ends are deflected ventrally and slightly expanded. Distal raphe fissures are semicircular and deflected dorsally. Striae are radiate throughout and indistinctly punctate. Areolae number 30-38 in 10 µm.
Original Description
Basionym: Cymbella subaequalis
Author: Grunow in Van Heurck 1880
Length Range: µm
Striae in 10 µm:
Original Description
Original Images
Cite This Page:
Bahls, L. (2012). Cymbopleura subaequalis. In Diatoms of the United States. Retrieved June 19, 2013, from http://westerndiatoms.colorado.edu/taxa/species/cymbopleura_subaequalis
Species: Cymbopleura subaequalis
Contributor: Loren Bahls
Reviewer: Sarah Spaulding
Image Credit: Loren Bahls
- Valves lanceolate to elliptic-lanceolate, slightly dorsiventral
- Apices weakly protracted
Cymbopleura subaequalis has lanceolate to elliptic-lanceolate valves, with arched dorsal and ventral margins and weakly protracted apices. Valves are somewhat dorsiventral.
Compare
Cymbopleura oblongata has nearly linear valves that are not, or only slightly, dorsiventral. Cymbopleura rupicola has lanceolate to rhombic-lanceolate valves, narrower apices and coarsely punctate striae.
Cymbopleura oblongata
Cymbopleura rupicola
Citations
Krammer, K. (2003). Cymbopleura, Delicata, Navicymbula, Gomphocymbellopsis, Afrocymbella. Diatoms of Europe. Diatoms of the European Inland Waters and Comparable Habitats 4: 1-530.
Patrick, R.M. and Reimer, C.W. (1975). The Diatoms of the United States, exclusive of Alaska and Hawaii, V. 2. Monographs of the Academy of Natural Sciences of Philadelphia 13.
Van Heurck, H. (1880). Synopsis des Diatomées de Belgique. Atlas. Ducaju & Cie., Anvers.
Links & ID's
Index Nominum Algarum (INA)
California Academy of Sciences (CAS)
North American Diatom Ecological Database (NADED)
NADED ID: 190017
Autecology Discussion
There are 45 records for C. subaequalis in the Montana Diatom Database from northwestern Montana, northern Idaho, and southwestern Alberta. The species is especially common and widespread in the Canadian Rockies (“Crown of the Continent”) Ecoregion, where it prefers cold, oligotrophic, and somewhat alkaline waters with low to moderate specific conductance. Krammer (2003) reports this species as cosmopolitan in temperate and colder regions in both the northern and southern hemispheres.
Images
Lake Josephine, Glacier National Park, Montana: home of Cymbopleura subaequalis.
Credit/Source: Loren Bahls