• Category
  • Length Range
    27-46 µm
  • Width Range
    9.5-14 µm
  • Striae in 10 µm
    9-11 dorsal in the center valve, 12-13 at apices



Valves are slightly dorsiventral, with slightly protracted apices. The dorsal margin is strongly arched and the ventral margin is moderately convex. The central area is small and elliptical. Two (sometimes three, and rarely one or four) stigmata are present at the end of the middle striae. The proximal raphe ends have central pores that curve to the ventral margin. The raphe is lateral, becoming filiform near the distal end. Striae are radiate. The areolae are apically elongated and number 22-24 in 10 μm.


Original Description

  • Author
    Grunow in Schmidt et al. 1875

Original Images

Cymbella turgidula orig illus

Cite This Page

Potapova, M. (2011). Cymbella turgidula. In Diatoms of North America. Retrieved May 24, 2024, from https://diatoms.org/species/cymbella_turgidula


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