Caloneis bacillum

(Grunow) Cleve 1894      Category: Symmetrical biraphid
BASIONYM: Stauroneis bacillum Grunow 1863

Caloneis amphisbaena


Caloneis lewisii

LM scalebar = 10 µm = 80 pixels.


Contributor: Pat Kociolek - March 2011
Length Range: 8-20 µm
Width Range: 3 µm
Striae in 10 µm: 25-29


Valves are linear to linear-lanceolate with rounded apices. The valve margins are straight to slightly convex in smaller specimens. The axial area is linear and expanded at the central valve to form a broad transverse fascia. The fascia is typically asymmetric from one side of the axial area to the other. The raphe is straight and filiform, with dilated proximal external ends. The striae are parallel to radiate. Longitudinal lines are visible in larger specimens.

Original Description

Basionym: Stauroneis bacillum
Author: Grunow 1863
Length Range: µm
Striae in 10 µm:

Original Description

Stauroneis Bacillum nov. spec. Stauroneis minor valvis anguste lineari oblongis apice rotundatis, nodulo centrali magno omnem valvae latitudinem occupante, striis transversis tenuissimis ultra 70 in 0.001”. Longit. 0.0010-0.0015”, latit. valvae 0.0002— 0.0003”. — Tab. nostr. 13 fig. 16 a, b (400/1). Habitat in aqua subsalsa ad litora Angliae prope Newhaven (legi August 1861). Die einzige mir bekannte ähnliche Art ist Stauroneis rectangularis Gregory , die aber durch grössere Gestalt, etwas stumpf vorgezogene Spitzen und viel stärkere Streifung hinreichend verschieden ist.

Original Images

Cite This Page:
Kociolek, P. (2011). Caloneis bacillum. In Diatoms of the United States. Retrieved April 24, 2018, from

Species: Caloneis bacillum

Contributor: Pat Kociolek

Reviewer: Sam Rushforth


Hustedt, F. (1930). Die Kieselalgen Deutschlands, Osterreichs und der Schweiz mit Berucksichtigung der ubrigen Lander Europas sowie der angrenzenden Meersgebiete. In: Dr. L. Rabenhorst's Kryptogamen-Flora von Deutschland, Osterreich und der Schweiz. Leipzig, Akademische Verlagsgesellschaft Geest und Portig K.-G. Vol. 7, Part 3, pp. 557-816.

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

Patrick, R.M. and Reimer, C.W. (1966). The Diatoms of the United States exclusive of Alaska and Hawaii, V. 1. Monographs of the Academy of Natural Sciences of Philadelphia 13.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Caloneis bacillum CAS

North American Diatom Ecological Database (NADED)

NADED ID: 12001

Autecology Discussion

EMAP Assessment

The Environmental Protection Agency (EPA) western Environmental Monitoring and Assessment Program (EMAP) study was completed during the years 2000-2004 (see citations at bottom of this page). Over 1200 streams and rivers in 12 western states (Arizona, California, Colorado, Idaho, Montana, Nevada, North Dakota, Oregon, South Dakota, Utah, Washington and Wyoming) were selected for sampling based on a stratified randomized design. This type of design insures that ecological resources are sampled in proportion to their actual geographical presence. Stratified randomized design also allows for estimates of stream length with a known confidence in several “condition classes” (good or least-disturbed, intermediately-disturbed, and poor or most-disturbed) for biotic condition, chemistry and habitat.

EMAP Distribution

Caloneis bacillum

EMAP Response Plots

Caloneis bacillum

EMAP citations

Results are published in:

Johnson, T., Hermann, K., Spaulding, S., Beyea, B., Theel, C., Sada, R., Bollman, W., Bowman, J., Larsen, A., Vining, K., Ostermiller, J., Petersen, D. Hargett, E. and Zumberge, J. (2009). An ecological assessment of USEPA Region 8 streams and rivers. U.S. Environmental Protection Agency Region 8 Report, 178 p.

Stoddard, J. L., Peck, D. V., Olsen, A. R., Larsen, D. P., Van Sickle, J., Hawkins, C. P., Hughes, R. M., Whittier, T. R., Lomnicky, G. A., Herlihy, A. T., Kaufman, P. R., Peterson, S. A., Ringold, P. L., Paulsen, S. G., and Blair, R. (2005). Environmental Monitoring and Assessment Program (EMAP) western streams and rivers statistical summary. U.S. Environmental Protection Agency Report 620/R-05/006, 1,762 p.

Stoddard, J. L., Peck, D. V., Paulsen, S. G., Van Sickle, J., Hawkins, C. P., Herlihy, A. T., Hughes, R. M., Kaufman, P. R., Larsen, D. P., Lomnicky, G. A., Olsen, A. R., Peterson, S. A., Ringold, P. L., and Whittier, T. R. (2005). An ecological assessment of western streams and rivers. U.S. Environmental Protection Agency Report 620/R-05/005, 49 p.