• Category
  • Length Range
    10.0-25.0 µm
  • Width Range
    3.0-5.0 µm
  • Striae in 10 µm



The valves are linear-elliptical, with the smallest valves elliptical in outline. The apices are rounded. The raphe has stout, distinct fibulae with a density of 7-9 in 10 ┬Ám. The middle two fibulae are closer together than the others. The striae are distinct, with the areolae being either not resolved, or indistinct.


Original Description

  • Author
    Lange-Bert. and Simonsen 1978
  • Length Range
    14.0-25.0 µm
  • Width
    3.5-4.0 µm
  • Striae in 10µm

Cite This Page

Kociolek, P. (2011). Nitzschia valdecostata. In Diatoms of North America. Retrieved May 24, 2024, from https://diatoms.org/species/nitzschia_valdecostata


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