• Reported As
    Cymbella norvegica (Foged 1981, p. 73, plate XLV, figs 12, 13)

Identification

Description

Valves are linear and weakly dorsiventral, with subrostrate apices. Dorsal and ventral margins are parallel and sometimes slightly tumid in the middle. The overall valve shape resembles a banana. The axial area is narrow and follows the mid line of the valve. The central area is a narrow transverse rectangle, interrupted occasionally on one or both margins by one or two short striae. The raphe is lateral and becomes filiform near the ends. External proximal raphe ends are weakly expanded and tipped toward the dorsal margin. Terminal raphe fissures are shaped like question marks and open toward the ventral margin. Striae are parallel to weakly radiate throughout. Areolae number 32-36 in 10 µm.

Autecology

This species is reported from Alaska (Foged 1981).The specimens presented on this page were collected from wet hummocks and in wetlands on the tundra of Nunavut, Canada (photos below). At the time of sampling, the pH of these waters was 7.15 and 6.90.

Wet Hummocks Off The  Baillie
Credit: Beverly Boynton, Adventurers and Scientists for Conservation
Wet hummocks along the Baillie River in Nunavut, northern Canada: home of Encyonema sibericum.
Wetland Off The  Back 1
Credit: Beverly Boynton, Adventurers and Scientists for Conservation
A wetland on the tundra along the Back River in northern Canada: home of Encyonema sibericum.
Wetland Off The  Back 2
Credit: Beverly Boynton, Adventurers and Scientists for Conservation
Closeup of the wetland in the image above.

Original Description

Areolae number 32-32 in 10 microns.

  • Author
    Krammer and Lange-Bert. 1999
  • Length Range
    30-45 µm
  • Width
    5.8-6.7 µm
  • Striae in 10µm
    12-14

Original Images

Encyonema sibericum orig illus
Encyonema Sibericum Origdesc001

Cite This Page

Bahls, L. (2017). Encyonema sibericum. In Diatoms of North America. Retrieved July 21, 2018, from https://diatoms.org/species/encyonema_sibericum

Responses

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