• Category
  • Diameter
    10-20 µm
  • Synonyms
    Eupodiscus weissflogii Grunow in Van Heurck 1882-1885
    Conticribra weissflogii (Grunow) Stachura-Suchoples and D.M.Williams 2009



Valves are round, flat, with short mantles. The frustules are relatively lightly silicified. Areolae are fine and details of their structure are not visible with the light microscope. A ring of marginal fultoportulae, with small external openings, are present. Three to six central fultoportulae are present near the center of the valve face. A single, prominent rimoportula is present on the margin of the valve.


Thalassiosira weissflogii is a planktonic diatom which commonly forms chains of widely spaced cells.

Original Description

  • Basionym
    Micropodiscus weissflogii
  • Author
    Grunow in Van Heurck 1880

Cite This Page

Kociolek, P. (2011). Thalassiosira weissflogii. In Diatoms of North America. Retrieved May 18, 2024, from https://diatoms.org/species/thalassiosira_weissflogii


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