• Category
  • 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.


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.

Gsm 7 15 05 3 Seep
Credit: Paula C. Furey
An image of a seep wall on Chimney Tops Trail in the Great Smoky Mountains National Park where E. kociolekii was abundant.

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.

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

Original Images

Eunotia Kociolekii Platescan I
Eunotia Kciolekii Platescan Ii
Eunotia Kociolekii  Textscan I

Cite This Page

Furey, P. (2011). Eunotia kociolekii. In Diatoms of North America. Retrieved July 17, 2018, from https://diatoms.org/species/eunotia_kociolekii


The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Eunotia kociolekii from all the stream reaches where it was present. Note that the relative abundance scale is the same on each plot. Explanation of each environmental variable and units are as follows:

ELEVATION = stream reach elevation (meters)
STRAHLER = distribution plot of the Strahler Stream Order
SLOPE = stream reach gradient (degrees)
W1_HALL = an index that is a measure of streamside (riparian) human activity that ranges from 0 - 10, with a value of 0 indicating of minimal disturbance to a value of 10 indicating severe disturbance.
PHSTVL = pH measured in a sealed syringe sample (pH units)
log_COND = log concentration of specific conductivity (µS/cm)
log_PTL = log concentration of total phosphorus (µg/L)
log_NO3 = log concentration of nitrate (µeq/L)
log_DOC = log concentration of dissolved organic carbon (mg/L)
log_SIO2 = log concentration of silicon (mg/L)
log_NA = log concentration of sodium (µeq/L)
log_HCO3 = log concentration of the bicarbonate ion (µeq/L)
EMBED = percent of the stream substrate that is embedded by sand and fine sediment
log_TURBIDITY = log of turbidity, a measure of cloudiness of water, in nephelometric turbidity units (NTU).
DISTOT = an index of total human disturbance in the watershed that ranges from 1 - 100, with a value of 0 indicating of minimal disturbance to a value of 100 indicating severe disturbance.