Diatoms of North AmericaDiatoms of North America

Encyonopsis albertana

Bahls 2013

Encyonopsis Albertana Guide
  • Category
    Asymmetric Biraphid
  • Length Range
    14.3-22.5 µm
  • Width Range
    3.1-4.1 µm
  • Striae in 10 µm
    20-24

Identification

Encyoalbertana1 Encyoalbertana2 Encyoalbertana3 Encyoalbertana4 Encyoalbertana5 Encyoalbertana6 Encyoalbertana7
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Description

Valves are narrowly lanceolate and moderately dorsiventral with rostrate apices slightly deflected ventrally. The dorsal margin is arched and the ventral margin is straight or weakly convex. The axial area is narrow, located about 1/3 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 radiate.

Autecology

Encyonopsis albertana is widely distributed and locally abundant in lakes, beaver ponds, and spring creeks in southwestern Alberta and northwestern Montana. These waters are alkaline (pH range 7.2-9.2) with moderate levels of dissolved solids (specific conductance range 141-255 μS/cm).

Encyonopsis albertana 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).

Blakiston Beaver Pond A 5
Credit: Barb Johnston, Parks Canada
Blakiston Beaver Pond A, Waterton Lakes National Park, Alberta: home of Encyonopsis albertana.
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

Valves narrowly lanceolate, moderately dorsiventral, dorsal margin arched, ventral margin straight or weakly convex. Valve length 14.3–22.5 μm; valve width 3.1–4.1 μm. Apices rostrate, deflected ventrally. Axial area narrow, about 1/3 the distance from the ventral margin to the dorsal margin. Central area very small, continuous with the axial area. Raphe branches filiform and bowed, concave to the dorsal margin. Proximal raphe ends unexpanded, deflected dorsally; distal raphe fissures hooked toward the ventral margin. Striae radiate, 20–24 in 10 μm.

  • Author
    Bahls 2013
  • Length Range
    14.3-22.5 µm
  • Width
    3.1-4.1 µm
  • Striae in 10µm
    20-24

Original Images

Encyo Albertana Origimag Cropped
Encyo Albertana Origdesc002

Cite This Page

Bahls, L. (2013). Encyonopsis albertana. In Diatoms of North America. Retrieved November 21, 2024, from https://diatoms.org/species/encyonopsis_albertana

Responses

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