Eunotia kociolekii

Furey, Lowe and Johansen 2011      Category: Eunotioid

Eunotia incisa


Eunotia lewisii

LM scalebar = 10 µm = 80 pixels.


Contributor: Paula Furey - March 2011
Length Range: 9-53 µm
Width Range: 4-8 µm
Striae in 10 µm: 12 -13 in the center valve, 14-20 at the ends


The dorsal margin is convex and slightly biundulate in larger valves and straight in smaller valves. The ventral margin is nearly straight, or only slightly concave. The apices are attenuated, truncated and apically flattened. The ends are slightly set off by a gradual change in slope of the dorsal margin. Helictoglossae are not visible under the LM. One apical rimoportula, with a prominent external pore, is present at the center of the apex (visible in SEM). Also under SEM, the internal openings of the areolae in E. kociolekii are aligned in a narrow groove. The distal raphe ends are curved and clearly visible in the LM. Striae are radiate. Areolae are 32-36 in 10µm. The cell length to width ratio increases with increases in cell size. Smaller cells have L:W of 2.5-3.5:1, while the largest cells have a L:W of 6-8:1.

Comparison of E. kociolekii to other species deserves further clarification. Eunotia kociolekii differs from the original type of E. diodon Ehrenberg (Ehrenberg 1837) by having smaller, narrower valves that are less strongly biundulate than E. diodon and apices that are more truncated and flattened than E. diodon. Subsequent floras present interpretations other than of the Ehrenberg type. Diatomists after Ehrenberg present E. diodon as relatively large and obtusely biundulate valves, 44 - 55 wide (see description in De Toni 1892; also Kützing 1849). In Schmidt’s Atlas (Hustedt 1911, Taf. 270: Figs 14 – 18), E. diodon includes a broad concept of biundulate morphologies with a range of widths and slopes along the dorsal edge to the apices. Eunotia diodon illustrated in Lange-Bertalot & Metzeltin (1996; Taf. 15: Figs 1-2) and Fig. 14 in Krammer & Lange-Bertalot (1991, Taf. 149) are similar in valve shape to E. kociolekii. Other images of “E. diodon” have a smaller length to width ratio (Lange-Bertalot & Metzeltin 1996; Taf. 15: Figs 1-2).

Eunotia kociolekii is longer than E. satelles Nörpel-Schempp et Lange-Bertalot (Lange-Bertalot & Metzeltin, 1996), but where the valves overlap in the lower size range, E. kociolekii could be confused with E. satelles. However, the smaller valves of E. satelles are wider and more steeply sloped towards the apices than E. kociolekii.

Original Description

Author: Furey, Lowe and Johansen 2011
Length Range: 9-53 µm
Width Range: 4-8 µm
Striae in 10 µm: 12 -13 in the center valve, 14-20 at the ends. puncta 32-36

Original Description

Valves only slightly concave to nearly straight on ventral margin, convex on dorsal margin slightly biundulate, straight in smallest valves, 9 – 53 μm long, 4 – 8 μm wide. Ends attenuated but neither constricted nor dorsally recurved, truncated and apically flattened, slightly set off by a gradual change in slope of the dorsal margin. Helictoglossae not visible under the light microscope. Rimoportula at one end of valve, at the center of the apex, with a prominent external pore. Raphe with distal ends curved and clearly visible in the light microscope. Striae radiate, radial at the apices after the last transverse stria at the helictoglossa, 12 – 13 in 10 μm in the valve center, 14 – 20 in 10 μm near the valve apices. Puncta 32 – 36 in 10 μm.

Original Images

Cite This Page:
Furey, P. (2011). Eunotia kociolekii. In Diatoms of the United States. Retrieved April 19, 2018, from

Species: Eunotia kociolekii

Contributor: Paula Furey

Reviewer: Sam Rushforth


Furey, P.C., Lowe, R.L. and Johansen, J.R. (2011). Eunotia Ehrenberg (Bacillariophyta) of the Great Smoky Mountains National Park, USA. Bibliotheca Diatomologica 56: 1-134.

Krammer, K. and Lange-Bertalot, H. (1991). Bacillariophyceae. 3. Teil: Centrales, Fragilariaceae, Eunotiaceae. In Ettl, H., Gerloff, J., Heynig, H. & Mollenhauer, D. (Eds.). Süsswasserflora von Mitteleuropa. 2(3): 1-576. Gustav Fisher Verlag, Stuttgart, Germany.

Lange-Bertalot, H. and Metzeltin, D. (1996). Indicators of oligotrophy - 800 taxa representative of three ecologically distinct lake types, Carbonate buffered - Oligodystrophic - Weakly buffered soft water. Lange-Bertalot, H. (ed.), Iconographia Diatomologica. Annotated Diatom Micrographs. Vol. 2. Ecology, Diversity, Taxonomy. Koeltz Scientific Books. Königstein, Germany, 2:390 pp.

Links & ID's

Index Nominum Algarum (INA)

California Academy of Sciences (CAS)

North American Diatom Ecological Database (NADED)


Autecology Discussion

To date, E. kociolekii has been found epiphytic on bryophytes in first through fifth order streams throughout the Great Smoky Mountains National Park, and was frequent on wet walls, occasionally in high abundance.


An image of a seep wall on Chimney Tops Trail in the Great Smoky Mountains National Park where E. kociolekii was abundant.

Credit/Source: Paula C. Furey