Valves are lanceolate with capitate apices. Raphe is slightly lateral, becoming filiform at the distal and proximal ends. Proximal raphe ends are straight and not inflated. The axial area is narrow and linear, barely wider than the raphe, flaring slightly into the central area. The central area is a narrow stauros. Striae are radiate throughout. Areolae are fine, round to oblong, irregularly spaced, and number 20-26 in 10 µm.
Stauroneis kootenai has been found in several lakes, ponds, fens, and low-gradient streams in western Montana. The pH of these waters ranges from 6.7 to 7.8 and specific conductance ranges from 22 to 169 µS/cm.
Valves lanceolate with capitate to subcapitate ends. Length 34-52 µm, width 8.1-10.3 µm. Raphe slightly lateral, becoming filiform at the distal and proximal endings. Proximal raphe ends small and straight, not inflated or deflected. Axial area narrow and linear, barely wider than the raphe, flaring slightly at the central area. Central area a narrow rectangular fascia. Striae radiate throughout, 20-28 in 10 µm. Striae puncta fine, round to oblong, and irregularly spaced, 20-26 in 10 µm. For measurements, n = 24 valves.
Bahls, L. (2011). Stauroneis kootenai. In Diatoms of North America. Retrieved November 14, 2024, from https://diatoms.org/species/stauroneis_kootenai
The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Stauroneis kootenai 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.