• Category
  • Length Range
    26.6-43.0 µm
  • Width Range
    9.3-12.6 µm
  • Striae in 10 µm
    9.9-15 at center of the valve, 15.7-20.8 near the apices
  • Synonyms
    Navicula integra (W.Sm.) Ralfs in A.Pritch. 1861



Valves are lanceolate to lanceolate-elliptical, with subrostrate apices. Near the apices, the valve margin undulates slightly to form a smooth hump, the width of which does not exceed the mid-breath of the valve. This smooth hump is present across the size range. Pseudosepta are present at the apices. The central area is small and elliptical. The axial area is linear. Striae are radial at the center of the valve, becoming nearly parallel at the apices. Striae are more widely spaced at the center of the valve and more dense near the apices. Striae may be offset, or they may be symmetric on either side of the axial area. Areolae are uniseriate and round to elliptical. Areolae can be resolved near the center of the valve, but less so near the apices. The internal proximal raphe ends are small and curved slightly in the same direction. The external proximal raphe ends are straight and expanded. The distal raphe ends are deflected unilaterally.

The species Prestauroneis tumida was described in Levkov and Williams (2011). However, the valve margin of P. integra is unique, and not likely to be confused with P. tumida.


Prestauroneis integra was found in plankton collected from a wave zone approximately 1 m offshore in Silver Lake, Dickinson County, Iowa. In this population, the length of P. integra clustered around the lower limit of the observed size range (26-35 µm). Specimens of P. integra from the Iowa Lakeside Lab Herbarium were found in a collection from Bessy Creek, Cheboygan County, Michigan. This population was closer to the maximum observed size range (37-43 µm). These observations demonstrate that a population within a single collection may not span the entire size range for the species. Distribution data from USGS BioData indicate that this taxon occurs near the Great Lakes and the northeastern coast (from Massachusetts to North Carolina). Prestauroneis integra “prefers waters with high mineral content, [and is] often found in polluted waters” (Patrick and Reimer, 1966, p. 474).

P Integra  Habitat
Credit: Mark Edlund
Image of Silver Lake, Dickinson County, Iowa, where P. integra was collected using a plankton net in the wave zone.
Karen  Prestauroneis Integra  Population  Size
Credit: Michigan specimens collected by Rex L. Lowe, ILL Collection L-3-14
Graph of the length and width measured in specimens of Prestauroneis integra from Silver Lake, Dickinson County, IA (smaller valves) and Bessy Creek, Cheboygan County, MI (larger valves).

Original Description

Valve elliptical-lanceolate, with a slight subterminal constriction and linear produced apices; striae indistinct, 36 in .001". Length of valve .0008". Greatest breadths of valve .0004".

  • Basionym
    Pinnularia integra
  • Author
    W.Sm. 1856

Original Images

N Integra Orig Des

Cite This Page

Neil, K. (2014). Prestauroneis integra. In Diatoms of North America. Retrieved June 21, 2024, from https://diatoms.org/species/prestauroneis_integra


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