• Category
  • Length Range
    56-280 µm
  • Width Range
    13-24 at the midsection, 15-36 at the broadest point µm
  • Striae in 10 µm
  • Synonyms
    Cymatopleura solea (Bréb. in Bréb. and Godey) W.Sm. 1851



Valves are broadly linear with a central constriction and tapering to blunt ends. Alar canals and ribs number 6-9 in 10 µm. Striations between the ribs are evident by fine, but not distinctly punctate striae. The raphe is contained in a canal around the margin of the valve. Undulations oriented across the face of the valve, occur the length of the valve.


As a relatively large diatom with a raphe system that runs the perimeter of the cell, S. librile is found growing on the surface of fine sediments.

The 2014 Ecology and Systematics of Diatoms course at the Iowa Lakeside Lab found a large population of S. librile at Triboji beach, West Lake Okoboji. In contrast to conventional thinking that sexual reproduction is induced near 40% of the maximum call size, the students found cells at 20% of the maximum cell size. As a class project, students searched for specific size ranges (~ 2 µm bins) to plot the dimensions. No auxospores or initial valves were observed.

Mann (1987) documented sexual reproduction in S. librile (=Cymatopleura solea) and a similar size range (1989).

Cymatopleura 2014 Copy
Credit: Ian Bishop
Size range of C. solea at Triboji beach. Scale bar equal to 100 µm.
C Solea Graphs
Credit: Ian Bishop, David Burge
Plots of the morphological dimensions of the cells found at Triboji beach.

Original Description

  • Basionym
    Navicula librile
  • Author
    Ehrenb. 1832

Original Images

Navicula Librile Orig Ill Jahn2017
Nav Librile Orig Descr

Citations & Links




Jun 30, 2014 - Extension of size range

Prior to 2014, length was documented as 57-177 µm, width as 14-20 µm at the midsection and 20-27 at the broadest point. Striae in 10 µm were 29-34. These values were revised based on the 2014 diatom class observations. See AUTECOLOGY tab for details. - S. Spaulding

May 19, 2020 - Taxonomic revision

From 2011 to 2020, this species was displayed on this webpage as Cymatopleura solea (Breb.) W. Smith 1851. Based on a molecular phylogeny, Ruck et al. (2016) demonstrated that Cymatopleura is nested within the Surirella lineage. Therefore, in order to maintain a classification that reflects monophyletic groups, C. solea was subsumed into Surirella. The earliest validly published name of this species within Surirella is S. librile (Ehrenb.) Ehrenb. 1845, based on Navicula librile Ehrenb. 1832 (Jahn et al. 2017). - M. Potapova

Cite This Page

Kociolek, P. (2011). Surirella librile. In Diatoms of North America. Retrieved July 24, 2024, from https://diatoms.org/species/surirella-librile


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