• Category
  • Length Range
    13.9-15.3 µm
  • Width Range
    3.8-4.8 µm
  • Striae in 10 µm



Valves are linear-lanceolate with triundulate margins and short rostrate-apiculate apices. Valves are widest at the center. A pseudoseptum is present at each apex. The axial area is very narrow and linear, becoming wider near the central area. The central stauros is narrow and linear. The raphe is filiform with straight and weakly inflated proximal ends. Striae are parallel at the center to weakly radiate near the apices. Areolae are very fine and difficult to resolve in LM.


Werum & Lange-Bertalot (2004) report that S. separanda is widely distributed in chalk-rich springs in Europe. It is probably also common in head-water habitats in North America, but under-reported here because of its close resemblance to the more familiar S. smithii.

Blakiston  Beaver  Pond  B  Detail 1
Credit: Barb Johnston, Parks Canada
Blakiston Beaver Pond A on Blakiston Creek in Waterton Lakes National Park, Alberta: home of Stauroneis separanda.

Original Description

  • Author
    Lange-Bert. and Werum in Werum and Lange-Bert. 2004
  • Length Range
    13-17 µm
  • Width
    3.6-4.7 µm
  • Striae in 10µm

Original Images

Stauroneis Separanda Origimag017
Stauroneis Separanda Origdesc016

Cite This Page

Bahls, L. (2012). Stauroneis separanda. In Diatoms of North America. Retrieved May 30, 2024, from https://diatoms.org/species/stauroneis_separanda


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