• Category
  • Length Range
    3.6– 11.0 µm
  • Width Range
    2.9–4.2 µm
  • Striae in 10 µm
  • Synonyms
    Planothidium bahlsii (M. Potapova) M.S. Kulikovskiy 2020



Valves are elliptic. Raphe valve has a narrow linear axial area and a small central area. Raphe is filiform, straight, with slightly expanded distal and proximal ends. Rapheless valve has a linear–lanceolate axial area. Striae are multiseriate, radiate. There are four rows of areolae per stria on the raphe valve, and three rows per stria on the rapheless valve.


Platessa bahlsii appears to be a common species in nutrient-rich streams of the eastern US.

Original Description

  • Author
    Potapova 2012
  • Length Range
    3.6-11.0 µm
  • Width
    2.9-4.2 µm
  • Striae in 10µm

Original Images

Pbahlsii  Or Ill A
Pbahlsii  Or Descr

Cite This Page

Potapova, M. (2012). Platessa bahlsii. In Diatoms of North America. Retrieved May 20, 2024, from https://diatoms.org/species/platessa_bahlsii


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