Valves are linear to linear-lanceolate and may often be subtly triundulate, with subrostrate rounded apices. The raphe is straight and filiform. The axial area is linear and narrow. The central area is elliptic and apically elongated. Striae are composed of a single areola, slightly radiate in the valve center, becoming parallel or slightly convergent toward the ends.
This taxon was described from Siberia. Specimens shown here are from Alaska.
Valvae lineares marginibus interdum minime undulatis apparentibus apicibus late rotundatis non vel parum protractis (attenuatis) sed numquam capitatis. Longitudo 15-27 µm, latitudo 3.3-4 µm. Raphe filiformis recta extremis centralibus terminalibusque inconspicuis tamen poris centralibus conspicue distantibus sitis inter se. Area axialis in partibus distalibus angusta ad mediam versus distincte dilatata. Area centralis satis lata rhombico-lanceolata ad instar. Striae transapicales modice radiantes sub apices distincte convergentes, 21-23 in 10 µm. In microscopo electronico: signa typica (particulariter alveoli simplices) generis Chamaepinnularia adsunt.
Leppik, S., Potapova, M. (2024). Chamaepinnularia krasskei. In Diatoms of North America. Retrieved November 23, 2024, from https://diatoms.org/species/chamaepinnularia-krasskei
The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Chamaepinnularia krasskei 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.