• Category
  • Length Range
    22.4-54.4 µm
  • Width Range
    7.6-11.4 µm
  • Striae in 10 µm
    10-14 at the valve center, 14-15 near the apices

Identification

Description

Valves are dorsiventral with rounded, weakly protracted apices. The dorsal margin is moderately arched. The ventral margin is concave with a gibbous central valve. The axial area is narrow and located just ventral of the apical axis. The central area is asymmetric and rounded, about one-third to one-half the valve width. The raphe is lateral, becoming filiform toward the proximal and distal ends. Proximal raphe ends are deflected ventrally and terminate in tear-shaped pores. Terminal raphe fissures are deflected dorsally. Striae are finely punctate and weakly radiate, becoming more strongly radiate near the apices. One to 5 isolated stigmata are located on the ventral side of the central nodule. Areolae number 22-30 in 10 μm.

Autecology

Cymbella blinnii has been recorded from alpine lakes in the Rocky Mountains, in Colorado and Montana (photo below).

Bullhead  L   Swiftcurrent  Pass
Credit: Loren Bahls
Bullhead Lake, Glacier National Park, Montana: home of Cymbella alpestris

Original Description

Valves are dorsiventral with rounded apices and moderately arched dorsal margins. Ventral margins are slightly concave with tumid centers in larger valves. Smaller valves have slightly convex ventral margins and weakly protracted apices. Valve length 22.8-51.6 μm; valve width 8.2-11.4 μm. Axial area is narrow and positioned just ventral of the apical axis. The central area is asymmetric and rounded, about one-third to one-half the valve width. The raphe is lateral. Proximal raphe ends are deflected ventrally and tipped with tear-shaped pores. Terminal raphe fissures are deflected dorsally. Striae are finely punctate and weakly radiate, becoming more strongly radiate near the apices. One to 5 isolated stigmata occur on the ventral side of the central nodule. Striae number 11- 14 in 10 μm at valve center to 14-15 in 10 μm at the apices (dorsal and ventral). Areolae number 25-30 in 10 μm.

  • Author
    L.L.Bahls 2014
  • Length Range
    22.8-51.6 µm
  • Width
    8.2-11.4 µm
  • Striae in 10µm
    11-14 at the valve center, 14-15 at the apices

Original Images

Cymbella blinnii orig illus

Cite This Page

Bahls, L. (2016). Cymbella blinnii. In Diatoms of North America. Retrieved July 21, 2018, from https://diatoms.org/species/cymbella_blinnii

Responses

The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Cymbella blinnii from all the stream reaches where it was present. Note that the relative abundance scale is the same on each plot. Explanation of each environmental variable and units are as follows:

ELEVATION = stream reach elevation (meters)
STRAHLER = distribution plot of the Strahler Stream Order
SLOPE = stream reach gradient (degrees)
W1_HALL = an index that is a measure of streamside (riparian) human activity that ranges from 0 - 10, with a value of 0 indicating of minimal disturbance to a value of 10 indicating severe disturbance.
PHSTVL = pH measured in a sealed syringe sample (pH units)
log_COND = log concentration of specific conductivity (µS/cm)
log_PTL = log concentration of total phosphorus (µg/L)
log_NO3 = log concentration of nitrate (µeq/L)
log_DOC = log concentration of dissolved organic carbon (mg/L)
log_SIO2 = log concentration of silicon (mg/L)
log_NA = log concentration of sodium (µeq/L)
log_HCO3 = log concentration of the bicarbonate ion (µeq/L)
EMBED = percent of the stream substrate that is embedded by sand and fine sediment
log_TURBIDITY = log of turbidity, a measure of cloudiness of water, in nephelometric turbidity units (NTU).
DISTOT = an index of total human disturbance in the watershed that ranges from 1 - 100, with a value of 0 indicating of minimal disturbance to a value of 100 indicating severe disturbance.