Valves are broadly lanceolate with abruptly protracted, narrow subcapitate apices. The axial area is narrow, widening gradually toward a large, rounded central area. The central area is 6-8 μm in diameter. The raphe is filiform to weakly lateral. Proximal raphe ends expanded and weakly deflected to one side. Terminal raphe fissures are curved, opening toward the secondary side. Striae are strongly radiate throughout most of valve, becoming parallel then convergent only near the apices. Striae number 12-14 in 10 μm. Areolae number 28-30 in 10 μm.
Navicula whitefishensis is known only from two lakes in the Northern Rocky Mountains of Montana: Upper Whitefish Lake, Flathead County (holotype locality) and Redrock Lake in Glacier National Park. Here pH measured 7.4 and 7.1, respectively, and specific conductance measured 130 and 94 µS/cm, respectively.
Valves broadly lanceolate with abruptly protracted and narrow subcapitate apices. Length 46-60 μm, width 11.3-14.2 μm. Axial area narrow, gradually widening toward a very large, rounded central area. Central area 5.9-8.2 μm in diameter. Raphe filiform to weakly lateral. Proximal raphe ends relatively distant, expanded and weakly deflected to one side. Terminal raphe fissures curved, opening toward the secondary side. Lineolate striae radiate almost throughout, becoming parallel then convergent only very near the poles, 12-14 in 10 μm. Areolae rather indistinct under LM, 28-30 in 10 μm.
Bahls, L. (2013). Navicula whitefishensis. In Diatoms of North America. Retrieved December 09, 2024, from https://diatoms.org/species/49245/navicula_whitefishensis
The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Navicula whitefishensis 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.