(W. Smith) Bruder 2008 Category: Symmetrical biraphid
BASIONYM: Pinnularia integra W. Smith 1856
SYNONYM(S): Navicula integra (W. Smith) Ralfs in Pritchard 1861
Contributor: Karen Neil - June 2014
Length Range: 27-43 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
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.
Basionym: Pinnularia integra
Author: W. Smith 1856
Length Range: µm
Striae in 10 µm:
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”.
Levkov, Z. and Williams, D.M. (2011). Fifteen new diatom (Bacillariophyta) species from Lake Ohrid, Macedonia. Phytotaxa 30: 1-41.
Smith, W. (1856). Synopsis of British Diatomaceae. John Van Voorst, London 1856. 2: 107pp., pls. 32-60, 61-62, A-E.
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).
Image of Silver Lake, Dickinson County, Iowa, where P. integra was collected using a plankton net in the wave zone.
Credit/Source: Mark Edlund
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).
Credit/Source: Michigan specimens collected by Rex L. Lowe, ILL Collection L-3-14