• Category
  • Length Range
    11.4-20.7 µm
  • Width Range
    2.9-4.4 µm
  • Striae in 10 µm
  • Reported As
    Encyonopsis krammeri (Krammer 1997, p. 99, figs 144: 12-15, 21; 145: 1-14, 16-18)



Valves are narrowly lanceolate and moderately dorsiventral with rostrate apices that are deflected slightly ventrally. The dorsal margin is arched and the ventral margin is straight or weakly convex. The axial area is narrow, located 1/3 to 1/2 the distance from the ventral margin to the dorsal margin. The central area is very small and continuous with the axial area. Raphe branches are filiform and bowed, concave to the dorsal margin. Proximal raphe ends are unexpanded and deflected dorsally. Distal raphe fissures are hooked toward the ventral margin. Striae are weakly radiate.


Encyonopsis krammeri has been collected from several lakes in the northern Rocky Mountains of northwest Montana. The pH of these lakes ranged from 8.0 to 9.1 and specific conductance ranged from 93 to 164 μS/cm.

Encyonopsis krammeri is one of many small-celled Encyonopsis and Encyonema species in the Northern Rockies (see plate below). Some of these may be ecomorphs of established species. All of these may be found in Krammer (1997) and Bahls (2013).

Bullhead  L
Credit: Loren Bahls
Bullhead Lake, Glacier National Park, Montana: home of Encyonopsis krammeri.
Small Encyonopsis Northern Rockies
Credit: Loren Bahls
Small-celled Encyonopsis (E.) and Encyonema taxa from the Northern Rockies. Some of these may be ecomorphs of established species (Bahls 2013, Krammer 1997).

Original Description

  • Author
    E.Reichardt 1997

Cite This Page

Bahls, L. (2013). Encyonopsis krammeri. In Diatoms of North America. Retrieved June 23, 2024, from https://diatoms.org/species/encyonopsis_krammeri


The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Encyonopsis krammeri 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.