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Diatoms of the United States is now known as Diatoms of North America.
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Chaetoceros muelleri

Lemmerm. 1898      Category: Centric

REPORTED AS: Chaetoceros elmorei (Boyer 1914) 

Cavinula vincentii


Chamaepinnularia mediocris

LM scalebar = 10 µm = 80 pixels.


Contributor: David R.L. Burge | Mark Edlund - June 2017
Diameter: 8.4-19.5 µm
Rows of areolae in 10 µm:


Cells form filamentous colonies, with neighboring valves linked by twisted setae that extend from the pole of each valve. Valves and setae are lightly silicified. Valves are elliptic. Dissociated frustules result in neighboring valves remaining connected valve face to valve face. The valve face of the intercalary cells are slightly convex. The terminal frustules of colonies have concave valve faces. The valve face lacks distinct ornamentation. A central process, however, (a rimoportula?) may aid in filament formation. The setae of the terminal valve are bent strongly away from the colony.

Internally formed resting spores (endogenous spores) are heavily silicified. Resting spores have a convex primary valve, and secondary valve with a prominent raised annulus.

Typical diatom sample preparation, such as hydrogen peroxide and nitric acid treatments, often dissolves the organic material that supports the lightly silicified valves and filaments.

The taxonomy of North American Chaeotoceros, particularly C. mueller and C. elmorei, has received attention (Johansen and Rushforth 1985, Rushforth and Johansen 1986, Johansen and Boyer 1995). Rushforth. Here we follow the conclusions reached by Johansen et al. (1990) who proposed synonymy of C. muelleri and C. elmorei based on culture studies. In culture, C. muelleri (single cells) and C. elmorei (chains) formed from the same clones. Chaetoceros muelleri is the older valid name, and has nomenclatural priority.

Original Description

Author: Lemmerm. 1898
Diameter: 9-10 µm
Mantle Height: 7 µm
Rows of areolae in 10 µm:

Original Description

Original Images

Cite This Page:
Burge, D., and Edlund, M. (2017). Chaetoceros muelleri. In Diatoms of the United States. Retrieved May 25, 2018, from

Species: Chaetoceros muelleri

Contributor: David R.L. Burge | Mark Edlund

Reviewer: Loren Bahls


Anderson, G.C. (1958). Seasonal characteristics of two saline lakes in Washington. Limnology and Oceanography 3(5): 51-68.

Bailey, L.W. (1922). Diatoms from the Quill Lakes, Saskatchewan, and from Airdrie, Alberta. Contributions to Canadian Biology 11: 157-165, II pl..

Boyer, C.S. (1914). A new diatom. Proceedings of the Academy of Natural Sciences of Philadelphia 66:219-221.

Fritz, S.C., Juggins, S., Battarbee, R.W. and Engstrom, D.R. (1991). Reconstruction of past changes in salinity and climate using a diatom-based transfer function. Nature 352: 706-708 . 10.1038/352706a0

Johansen, J.R. and Rushforth, S.R. (1985). A contribution to the taxonomy of Chaetocerus muelleri Lemmerman (Bacillariophycae) and related taxa. Phycologia 24: 437-447.

Johansen, J.R., Barclay, W.R. and Nagle, N. (1990). Physiological variability within ten strains of Chaetoceros muelleri (Bacillariophyceae). Journal of Phycology 26: 271-278.

Lemmermann, E. (1898). Der grosse Waterneverstorfer Binnensee. Eine biologische Studie. Forschungsberichte aus der Biologischen Station zu Plön 6: 166-205, 4 figs, 1 map, pl. V.

Rushforth, S.R. and Johansen, J.R. (1986). The inland Chaetoceros (Bacillariophyceae) species of North America. Journal of Phycology 22: 441-448.

Saros, J.E. and Fritz, S.C. (2002). Resource competition among saline-lake diatoms under varying N/P ratio, salinity and anion composition. Freshwater Biology 47: 87.

Wang, S., Lambert, W., Giang, S., Goericke, R. and Palenik, B. (2014). Microalgal assemblages in a poikilohaline pond. Journal of Phycology 50: 303-309.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Chaetoceros muelleri CAS

North American Diatom Ecological Database (NADED)

NADED ID: 15002

Autecology Discussion

Chaetoceros muelleri is a colonial planktonic species most often found in endorheic saline environments, such as Devil’s Lake, North Dakota (Boyer 1914 as Chaetoceros elmorei). Anderson (1958, as C. elmorei) found C. muelleri plankton abundance peaked in mid-summer in saline lakes of Washington state. Bailey (1922, as C. elmorei) reports this taxon from saline lakes in Saskatchewan. Wang et al. (2014) reported Chaetoceros muelleri in saline ponds in California. In a study of inland saline lakes on the Northern Great Plains, C. muelleri was most associated with sulphate-based salinity (Saros and Fritz 2002, as C. elmorei). A single endogenous resting spore is produced by each cell presumably as a dormancy response to inimical conditions; spores are widely used as an indicator of salinity in paleoclimate projects (Fritz et al. 1991).


Credit/Source: Image from ILL 2006-56

The distribution of Chaetoceros elmorei in streams of the contiguous 48 United States. Accessed on 7 June 2017.

Credit/Source: USGS/Biodata