• Category
  • Length Range
    14-34 µm
  • Width Range
    7-9.5 µm
  • Striae in 10 µm



Valves 14-34 µm long by 7-9.5 µm wide, with a length-width ratio between 2 and 3.6. Valves generally clavate, although some have linear or constricted midsections that abruptly become pointed near the footpole. The headpole is broadly rounded while the footpole is acutely wedge-shaped and frequently capitate. Costae extend from the valve margins to the apical axis, 30-36 in 10 µm and rarely visible in the LM. Between the costae 2-3 rows of areolae exist, which are only visible in the SEM. Indentations in the valve face are present around the circumference of the valve, having the appearance of large areolae in the LM. Fibulae are short and marginal, 9-12 in 10µm.


Original Description

  • Author
    Grunow in Van Heurck 1881

Original Images


Cite This Page

English, J. (2011). Surirella suecica. In Diatoms of North America. Retrieved May 29, 2024, from https://diatoms.org/species/surirella_suecica


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