Cymbella cosleyi

Bahls 2013      Category: Asymmetrical biraphid
BASIONYM: Cymbella cosleyi Bahls 2013

Cymbella amplificata

 

Cymbella excisiformis

LM scalebar = 10 µm = 80 pixels.



Observations

Contributor: Loren Bahls - October 2012
Length Range: 20-31 µm
Width Range: 5.5-7.1 µm
Striae in 10 µm: 10-12 at the valve center, 14-16 near the apices

Description

Valves are distinctly dorsiventral, with subrostrate or rounded apices. The dorsal margin is strongly arched. The ventral margin is nearly flat or weakly concave and slightly gibbous in the middle. The axial area is narrow. The central area is small and asymmetric, rounded on the dorsal side and flat on the ventral side. The raphe is lateral, becoming reverse-lateral near the proximal ends. The proximal raphe ends are deflected ventrally, with slightly expanded terminal fissures. Distal raphe fissures are deflected dorsally. Striae are slightly radiate near the middle, becoming more strongly radiate near the apices. Two indistinct stigmata are present at the ends of two central, ventral striae. Central, dorsal areolae are easily resolved under LM and number 28-30 in 10 µm.



Original Description

Basionym: Cymbella cosleyi
Author: Bahls 2013
Length Range: 20-31 µm
Width Range: 5.5-7.1 µm
Striae in 10 µm: 10-12 at valve center, 14-16 near the apices

Original Description

Valves distinctly dorsiventral with subrostrate or simply rounded apices. Dorsal margin strongly arched, ventral margin nearly flat or weakly concave and slightly gibbous in the middle. Valve length 20–31 μm; valve width 5.5–7.1 μm. Axial area narrow, central area small and asymmetric, rounded on the dorsal side and flat on the ventral side. Raphe lateral, becoming reverse-lateral near the proximal pores, which are slightly expanded. Proximal raphe ends deflected ventrally, then recurved slightly toward the dorsal margin. Distal raphe ends deflected dorsally. Striae slightly radiate near valve middle, becoming more strongly radiate near apices, 10–12 at valve center, 14–16 near apices. Two indistinct stigmata at ends of middle ventral striae. Areolae easily resolved under LM, 28–30 in 10 μm.

Original Images


Cite This Page:
Bahls, L. (2012). Cymbella cosleyi. In Diatoms of the United States. Retrieved April 25, 2014, from http://westerndiatoms.colorado.edu/taxa/species/cymbella_cosleyi

Species: Cymbella cosleyi

Contributor: Loren Bahls

Reviewer: Sarah Spaulding

Citations

Bahls, L. (2013). New diatoms (Bacillariophyta) from western North America. Phytotaxa 82(1): 7-28.

McClung, B. (1998). Belly River’s Famous Joe Cosley. Life Preservers, Kalispell. 182 pp.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

North American Diatom Ecological Database (NADED)

NADED ID:

Autecology Discussion

Cymbella cosleyi has been collected from four lakes and rivers in Glacier National Park, Montana and Waterton Lakes National Park, Alberta. These waters have somewhat alkaline pH (7.80-8.54) and low specific conductance (92-209 µS/cm).

Images

Bowman Lake, Glacier National Park, Montana: type locality for Cymbella cosleyi.

Credit/Source: Loren Bahls

Belly River in Waterton Lakes National Park, Alberta: historic home ground of Joe Cosley and current home of Cymbella cosleyi.

Credit/Source: Barb Johnston, Parks Canada