Aneumastus minor

Lange-Bertalot 1993      Category: Symmetrical biraphid
BASIONYM: Aneumastus minor Lange-Bertalot 1993
SYNONYM(S): Navicula tuscula f. minor Hustedt 1930 | Aneumastus tusculus f. minor  (Hustedt) Bukhtiyarova 1995 | Aneumastus tuscula f. minor Andresen, Stoermer and Kreis 2000 

Amphora pediculus


Aneumastus pseudotusculus

LM scalebar = 10 µm = 80 pixels.


Contributor: Loren Bahls - December 2012
Length Range: 18-35 µm
Width Range: 9.0-11.7 µm
Striae in 10 µm: 12-14


Valves are elliptic to broadly lanceolate with acutely rounded and sometimes slightly protracted apices. Axial area is narrow and linear in small specimens to narrowly lanceolate in larger specimens. Central area is a transverse fascia delimited by 3-4 irregularly shortened striae on each side. The raphe is weakly lateral and somewhat undulate with distinctly dilated proximal ends. Striae are radiate throughout. Areolae in the central region are transapically elongate and number 8-12 in 10 µm. Areolae are secondarily aligned in 1-2 undulate longitudinal rows alternating with longitudinal hyaline areas.

Hustedt (1930) published an illustration of Navicula tuscula fo. minor without a description and thus the name is invalid. Lange-Bertalot (1993) intended to publish Aneumastus minor in as a new combination of this taxon, but instead he effectively published a new taxon.

Original Description

Basionym: Aneumastus minor
Author: Lange-Bertalot 1993
Length Range: 15-35 µm
Width Range: 8-12 µm
Striae in 10 µm: 11-13

Original Description

Original Images

Cite This Page:
Bahls, L. (2012). Aneumastus minor. In Diatoms of the United States. Retrieved August 24, 2016, from

Species: Aneumastus minor

Contributor: Loren Bahls

Reviewer: Mark Edlund


Hustedt, F. (1922). Die Bacillariaceen-Vegetation des Lunzer Seengebietes (Nieder-Österreich). Internationale Revue der gesamten Hydrobiologie und Hydrographie 10(1-2): 40-74, 233-270.

Hustedt, F. (1930). Bacillariophyta (Diatomeae). In: Die Subwasser Flora Mitteleuropas. (A. Pascher, ed.),10, Gustav Fischer, Jena. 468 pp.

Krammer, K. and Lange-Bertalot, H. (1986). Bacillariophyceae. 1. Teil: Naviculaceae. In: Ettl, H., J. Gerloff, H. Heynig and D. Mollenhauer (eds.) Susswasserflora von Mitteleuropa, Band 2/1. Gustav Fisher Verlag, Jena. 876 pp.

Lange-Bertalot, H. (1993). 85 Neue taxa und uber 100 weitere neu definierte Taxa erganzend zur Subwasserflora von Mittleuropa. Bibliotheca Diatomologica 27, 454 p. Cramer, Berlin, Stuttgart.

Lange-Bertalot, H. (2001). Navicula sensu stricto, 10 genera separated from Navicula sensu lato, Frustulia. Diatoms of Europe 2: 1-526.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Aneumastus minor CAS

North American Diatom Ecological Database (NADED)

NADED ID: 105007

Autecology Discussion

Aneumastus minor has been collected from mountain lakes and rivers in western Montana and from slow-moving streams on the Northwestern Great Plains. One of these sites, Big Therriault Lake (shown below) had a pH of 9.05 and a specific conductance of 176 µS/cm on the sampling date. Lange-Bertalot (2001) reports that this species prefers eutrophic, chalk-rich standing waters. Although also found in remote and relatively pristine waters, It is perhaps the most tolerant of pollution among Aneumastus species in the United States.


Big Therriault Lake, Ten Lakes Scenic Area, Kootenai National Forest, Montana: home of Aneumastus minor.

Credit/Source: Loren Bahls