• Category
  • Length Range
    19-30 µm
  • Width Range
    10-13 µm
  • Striae in 10 µm



Valves are ovate, with a broadly rounded headpole and rounded to narrowly cuneate footpole. The valve face is slightly concentrically undulate. The keel is low. The striae are radiate at the apices, parallel in the middle of the valve, and extend from the margin to the midline. The striae consist of 2-4 rows of areolae situated between costae. Marginal fibulae number 6–8 in 10 μm. The costae extending from the fibulae are raised above internal valve surface from the valve margin half-way toward the midline.


Surirella lacrimula is common in rivers of temperate zone. However, this taxon was often misidentified as S. minuta or other Surirella species. As a result, its autecology has not been clarified.

Original Description

  • Author
    J.D.English 2012
  • Length Range
    19-30 µm
  • Width
    10-13 µm
  • Striae in 10µm

Original Images

Surilacrimula Orig Ill1
Surilacrimula Orig Descr

Cite This Page

Potapova, M. (2020). Surirella lacrimula. In Diatoms of North America. Retrieved April 21, 2024, from https://diatoms.org/species/surirella-lacrimula


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