Sellaphora saugerresii

(Desmazières) Wetzel and Mann 2015      Category: Symmetrical biraphid
BASIONYM: Navicula saugerrei Desmazières 1858

REPORTED AS: Navicula minima (Grunow in Van Heurck 1880, pl. 14, fig. 15) | Navicula seminulum (Grunow sensu Krammer and Lange Bertalot 1986, p. 230, pl. 76, figs 30-36) | Sellaphora seminulum ((Grunow) Mann sensu Hofmann et al. 2011, p. 537, pl. 42, figs 22-26) 

Sellaphora rexii

 

Sellaphora stauroneioides

LM scalebar = 10 µm = 80 pixels.



Observations

Contributor: Alison Minerovic - May 2016
Length Range: 7-12 µm
Width Range: 3.1-3.5 µm
Striae in 10 µm: 20-22

Description

Valves are linear-elliptic to linear-lanceolate with rounded ends. The axial area is narrow and straight. The central area is wide, more or less symmetric, and bow-tie shaped with two or three shorter, uneven striae. Striae are slightly radiate near the central area, becoming very parallel toward the poles. Striae may be resolved under optimal lighting in LM. In SEM, striae are seen to be biseriate and become uniseriate toward the axial area. Areolae are not resolvable under LM, but under SEM are small and round. The raphe is straight with slightly curved, tear-drop-shaped proximal ends. Terminal raphe fissures are curved toward the same side of the valve. Polar bars are absent.

There has been much confusion regarding the taxonomic identity of Sellaphora saugerresii and related species. The recent treatment of the former Eolimna minima and Sellaphora seminulum species complexes are further explained in Wetzel et al. (2015), and the specimens examined here appear to agree with the treatment of S. saugerresii described by the authors. Note that, some years back Sellaphora saugerresii was described as a ‘doubtful synonym’ of Navicula seminulum by Krammer and Lange-Bertalot (1986, p. 230), but we consider that the Lange-Bertalot images do, indeed, show S. saugerresii.



Original Description

Basionym: Navicula saugerrei
Author: Desmazières 1858
Length Range: 13 µm
Width Range: 5 µm
Striae in 10 µm:

Original Description

N. minutissima, laevis, lanceolato-elliptica, apicibus parum acutis vel obtusis. Long. 0.013 mm; lat. 0.005 mm. Altero latere oblonga truncata. Viva in aqua antilae inclusa in lagena.

Original Images


Cite This Page:
Minerovic, A. (2016). Sellaphora saugerresii. In Diatoms of the United States. Retrieved June 26, 2017, from http://westerndiatoms.colorado.edu/taxa/species/sellaphora_saugerresii

Species: Sellaphora saugerresii

Contributor: Alison Minerovic

Reviewer: Eduardo Morales

Citations

Wetzel, C.E., Ector, L., Van de Vijver, B., Compère, P. and Mann, D.G. (2015). Morphology, typification and critical analysis of some ecologically important small naviculoid species (Bacillariophyta). Fottea, Olomouc 15(2): 203–234. 10.5507/fot.2015.020

Links & ID's

Index Nominum Algarum (INA)

California Academy of Sciences (CAS)

Sellaphora saugerresii CAS

North American Diatom Ecological Database (NADED)

NADED ID: 170134

Autecology Discussion

There has been much confusion regarding the taxonomic identity of Sellaphora saugerresii and related species. The recent treatment of the former Eolimna minima and Sellaphora seminulum species complexes are further explained in Wetzel et al. (2015), and the specimens examined here appear to agree with the treatment of S. saugerresii described by the authors. Because small-celled naviculoid taxa are often dominant in benthic freshwater communities, they are considered ecologically important taxa and in need of revision and further scrutiny. The recent treatment by Wetzel et al. (2015) will aid in clarifying the habitat preferences and distribution of S. saugerresii and related taxa.