Valves are dorsiventral and lanceolate with rounded apices. The dorsal margin is moderately arched; the ventral margin is weakly convex to nearly flat in the largest specimens. The central area is a somewhat wider continuation of the axial area, otherwise not distinguished. The raphe is distinctly lateral and bowed, narrowing toward the proximal and terminal ends. Proximal raphe ends are deflected ventrally. Distal raphe fissures are deflected dorsally at about a 45 degree angle. Striae are nearly parallel at the valve center, becoming radiate near the apices. The areolae are distinct in LM and number 20-24 in 10 µm. Stigmata are lacking.
The specimens of Cymbella subleptoceros shown on this web page are from a riparian wetland in northwestern Montana. At the time of collection, pH measured 7.40 and specific conductance measured 460 µS/cm. Krammer (2002) reports this taxon in Europe from mesotrophic waters with average electrolyte content.
Bahls, L. (2016). Cymbella subleptoceros. In Diatoms of North America. Retrieved December 03, 2024, from https://diatoms.org/species/cymbella_subleptoceros
The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Cymbella subleptoceros 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.