• Category
  • Length Range
    29.7-48.3 µm
  • Width Range
    6.9-8.1 µm
  • Striae in 10 µm
  • Reported As
    Cymbella hybrida (Patrick and Reimer 1975, p. 32, plate 4, fig. 10)
    Cymbella hybrida (Krammer and Lange-Bertalot 1975, p. 337, figs 145: 1,3)



Valves are linear and nearly symmetric on either side of the apical axis. Valve margins are parallel to slightly convex. Apices are subrostrate to subcapitate. The axial area is narrow and follows the valve midline. The central area is large and rounded, and reaches nearly to the valve margins. The raphe is lateral and becomes filiform toward the proximal and distal ends. Proximal raphe ends are slightly expanded and tipped slightly toward the ventral side. Distal raphe fissures are deflected dorsally. Striae are slightly radiate throughout and sometimes curved, especially about the central area. Short striae about the central area are more widely spaced and striae near the valve ends are more closely spaced. Areolae in the striae are not visible in LM.


Patrick & Reimer (1975) report this species from Connecticut, South Carolina, Michigan, and Montana. Krammer (2003) reports Cymbopleura hybrida from arctic, sub-arctic, and alpine regions where it prefers oligotrophic waters with low to moderate electrolyte content. The specimens shown here were collected from a tundra lake above the Arctic Circle in Nunavut, Canada (photo below).

Sample 10 2
Credit: Beverly Boynton, Adventurers and Scientists for Conservation
Bloody Falls Tundra Lake, Nunavut, Canada: home of Cymbopleura hybrida.

Original Description

  • Basionym
    Cymbella hybrida
  • Author
    Grunow 1878
  • Length Range
    45 µm
  • Width
    9.0 µm
  • Striae in 10µm

Original Images

Cymbella hybrida orig illus
Cymbella hybrida orig orig descr

Cite This Page

Bahls, L. (2015). Cymbopleura hybrida. In Diatoms of North America. Retrieved July 13, 2024, from https://diatoms.org/species/cymbopleura_hybrida1


The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Cymbopleura hybrida 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.