Thalassiosira weissflogii

(Grunow) G.A.Fryxell and Hasle 1977      Category: Centric
BASIONYM: Micropodiscus weissflogii Grunow in Van Heurck 1880
SYNONYM(S): Eupodiscus weissflogii Grunow in Van Heurck 1882-1885 | Conticribra weissflogii  (Grunow) Stachura-Suchoples and D.M.Williams 2009 

Thalassiosira lacustris


Tryblionella apiculata

LM scalebar = 10 µm = 80 pixels.


Contributor: Pat Kociolek - March 2011
Diameter: 10-20 µm
Rows of areolae in 10 µm:


Valves are round, flat, with short mantles. The frustules are relatively lightly silicified. Areolae are fine and details of their structure are not visible with the light microscope. A ring of marginal fultoportulae, with small external openings, are present. Three to six central fultoportulae are present near the center of the valve face. A single, prominent rimoportula is present on the margin of the valve.

Original Description

Basionym: Micropodiscus weissflogii
Author: Grunow in Van Heurck 1880
Diameter: µm
Rows of areolae in 10 µm:

Original Description

Original Images

Cite This Page:
Kociolek, P. (2011). Thalassiosira weissflogii. In Diatoms of the United States. Retrieved April 23, 2018, from

Species: Thalassiosira weissflogii

Contributor: Pat Kociolek

Reviewer: Sam Rushforth


Hasle, G.R. and Fryxell, G.A. (1977). The genus Thalassiosira: some species with a linear areola array. In: R. Simonsen (ed.), Proceedings of the Fourth Symposium on Recent and Fossil Marine Diatoms, Oslo, 1976. Beihefte zur Nova Hedwigia 54:15-66.

Stachura-Suchoples, K. and Williams, D.M. (2009). Description of Conticribra tricircularis, a new genus and species of Thalassiosirales, with a discussion on its relationship to other continuous cribra species of Thalassiosira Cleve (Bacillariophyta) and its freshwater origin. European Journal of Phycology, 44(4): 477-486. 10.1080/09670260903225431

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Thalassiosira weissflogii CAS

NCBI Genbank Taxonomy

Thalassiosira weissflogii NCBI

North American Diatom Ecological Database (NADED)

NADED ID: 70008

Autecology Discussion

Thalassiosira weissflogii is a planktonic diatom which commonly forms chains of widely spaced cells.

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

Thalassiosira weissflogii

EMAP Response Plots

Thalassiosira weissflogii

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.