Diploneis finnica

(Ehrenb.) Cleve 1891      Category: Symmetrical biraphid
BASIONYM: Cocconeis finnica Ehrenb. 1838

Diploneis elliptica


Diploneis krammeri

LM scalebar = 10 µm = 20 pixels.


Contributor: Loren Bahls - December 2011
Length Range: 52-107 µm
Width Range: 33-53 µm
Striae in 10 µm: 7-9


Valves are broadly elliptical. The longitudinal canals are a distinctive lanceolate shape about 1/3 to 1/2 the width of the valve at center, which narrows towards the valve apices. The axial area is occupied almost completely by a broad raphe sternum that encloses the raphe. The central area is small and elliptical. Striae consist of double rows of areolae, one row may appear more prominent than the adjacent row. Striae are radiate throughout and extend onto the longitudinal canals. Areolae are distinct in LM and number 12-14 in 10 µm, but are more closely spaced over the longitudinal canals.

Original Description

Basionym: Cocconeis finnica
Author: Ehrenb. 1838
Length Range: µm
Striae in 10 µm:

Original Description

Original Images

Cite This Page:
Bahls, L. (2011). Diploneis finnica. In Diatoms of the United States. Retrieved April 24, 2018, from http://westerndiatoms.colorado.edu/taxa/species/diploneis_finnica

Species: Diploneis finnica

Contributor: Loren Bahls

Reviewer: Sarah Spaulding


Cleve, P.T. (1891). The Diatoms of Finland. Actas Societas Pro Fauna et Flora Fennica 8 (2): 1-68.

Ehrenberg, C.G. (1838). Die Infusionsthierchen als vollkommene Organismen. Ein Blick in das tiefere organische Leben de Natur. erlag von Leopold Voss, Leipzig. pp. 1-xvii, 1-548, pls. 1-64.

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)

Diploneis finnica CAS

North American Diatom Ecological Database (NADED)

NADED ID: 30002

Autecology Discussion

Diploneis finnica is a northern species. There are seven records of this species in the Montana Diatom Collection from lakes and streams in western Montana and northern Idaho. The pH of these waters ranges from 7.4 to 8.2 and specific conductance ranges from 39 to 90 µS/cm. Patrick and Reimer (1966) report Diploneis finnica from New England and the Pacific Northwest in “fresh water, particularly standing water, indifferent to small amounts of salt”. As the specific epithet suggests, the type locality of this species is in Finland.


Ross Creek, Lincoln County, northwest Montana: home of Diploneis finnica.

Credit/Source: Realty-Northwest.com