• Category
  • Length Range
    10-29 µm
  • Width Range
    3.8-6.3 µm
  • Striae in 10 µm
    29-33

Identification

Description

Valves are lanceolate to linear-elliptic with rounded to slightly drawn-out ends. Striae are radiate. Axial area is rhombic-lanceolate. Central area is asymmetric, reaching valve margin on one side of the valve. The raphe is absent on one of the valves. The raphe has a double-curved external slit and straight internal slit. External proximal raphe ends are simple or slightly expanded, internal proximal raphe slits are T-shaped.

Autecology

Original Description

Valves lanceolate to linear-elliptical with rounded to slightly drawn-out ends, 3.8–6.3μm wide, 10– 29μm long. Striae radiate, 29–33 in 10μm. Axial area rhombic-lanceolate. Central area asymmetrical, reaching the valve margin on one side of the valve. The raphe absent on one of the valves. The raphe with double-curved external slit and straight internal slit. External proximal raphe ends simple or slightly expanded, internal proximal raphe slits T-shaped. Terminal raphe fissures deflected towards secondary side of the valve.

  • Author
    Potapova 2011
  • Length Range
    10-29 µm
  • Width
    3.8-6.3 µm
  • Striae in 10µm
    29-33

Original Images

Nupela Frezelii Orig Image
Nupela Frezelii Orig Image Sem

Cite This Page

Potapova, M. (2010). Nupela frezelii. In Diatoms of North America. Retrieved August 20, 2018, from https://diatoms.org/species/nupela_frezelii

Responses

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