Muelleria gibbula

(Cleve) S.A.Spauld. and Stoermer 1997      Category: Symmetrical biraphid
BASIONYM: Navicula gibbula Cleve 1894

REPORTED AS: Muelleria ambigua (Kociolek 2014, p. 40, pl. 54, figs 6-12) 

Muelleria agnellus


Muelleria spauldingiae

LM scalebar = 10 µm = 80 pixels.


Contributor: Loren Bahls - March 2016
Length Range: 21-40 µm
Width Range: 6.8-9.6 µm
Striae in 10 µm: 18-22 at the valve center, 22-26 at the ends


Valves are elliptic-lanceolate to linear in the largest specimens. The central margin is typically gibbous although some specimens lack a central inflation. Apices are broadly rounded. The raphe is straight and situated between two longitudinal canals. The axial area is narrow and linear, widening slightly near the small, elliptic central area. Proximal raphe ends are unilaterally deflected. Internally, a rectelevatum is present between the two raphe branches, typical for the genus Muelleria. Striae are radiate throughout, the central striae more widely spaced than in the rest of the valve. Areolae in the central striae appear larger and more distinct than areolae in more distal striae. Copulae are evident in girdle view in some specimens. External SEM images show simple round areolae openings, unilaterally bent proximal raphe ends that do not enter the first row of areolae, and bifurcating distal raphe fissures that separate at a wide angle due to the position of a large siliceous flap.

Original Description

Basionym: Navicula gibbula
Author: Cleve 1894
Length Range: 33-43 µm
Width Range: 8.5-10 µm
Striae in 10 µm: 16 (middle), 21 (ends)

Original Description

Original Images

Cite This Page:
Bahls, L. (2016). Muelleria gibbula. In Diatoms of the United States. Retrieved April 20, 2018, from

Species: Muelleria gibbula

Contributor: Loren Bahls

Reviewer: Bart Van de Vijver


Cleve, P.T. (1894). Synopsis of the Naviculoid Diatoms, Part I. Kongliga Svenska-Vetenskaps Akademiens Handlingar 26(2):1-194, 5 pls.

Kociolek, J.P., Laslandes, B., Bennett, D., Thomas, E., Brady, M. and Graeff, C. (2014). Diatoms of the United States 1: Taxonomy, Ultrastructure and Descriptions of New Species and Other Rarely Reported Taxa from Lake Sediments in the Western U.S.A. Bibliotheca Diatomologica 61, J. Cramer, Stuttgart.

Lagerstedt, N.G.W. (1873). Sötvattens-Diatomaceer från Spetsbergen och Beeren Eiland. Bihang till Kongliga Svenska Vetenskaps-Akademiens Handlingar 1 (14): 1-52, 2 pls.

Spaulding, S.A. and Stoermer, E.F. (1997). Taxonomy and distribution of the genus Muelleria Frenguelli. Diatom Research 12: 95-113.

Spaulding, S.A., Kociolek, J.P. and Wong, D. (1999). A taxonomic and systematic revision of the genus Muelleria (Bacillariophyta). Phycologia 38: 314-341.

Links & ID's

Index Nominum Algarum (INA)

Transfer INA
Transfer INA
Original INA

California Academy of Sciences (CAS)

Muelleria gibbula CAS

North American Diatom Ecological Database (NADED)

NADED ID: 215001

Autecology Discussion

Muelleria gibbula has been reported from a wide range of soft water, shallow water, soil and aerophilic habitats (Spaulding et al. 1999). Specimens of Muelleria gibbula pictured on this web page were collected from a small alpine tarn in Grand Teton National Park, Wyoming and a mossy pool high in the Mission Mountains of Montana (photos below).


Alpine tarn at 9801 feet elevation in the northern Teton Range, Teton County, Wyoming: home of Muelleria gibbula.

Credit/Source: Beverly Boynton, Adventurers and Scientists for Conservation

Sample site where Muelleria gibbula was collected in the alpine tarn pictured above.

Credit/Source: Beverly Boynton, Adventurers and Scientists for Conservation

Mossy pool in the Mission Mountains, Missoula County, Montana: home of Muelleria gibbula.

Credit/Source: Bill Agnew, Adventurers and Scientists for Conservation