Diatoms of North AmericaDiatoms of North America

Encyonopsis lacusalpini

Bahls 2013

Encyonopsis Lacusalpini Guide
  • Category
    Asymmetric Biraphid
  • Length Range
    11.3-12.6 µm
  • Width Range
    3.0-3.4 µm
  • Striae in 10 µm
    26-29

Identification

Encyonopsislacusalpinus1 Encyonopsislacusalpinus2 Encyonopsislacusalpinus5 Encyonopsislacusalpinus3 Encyonopsislacusalpinus4 Encyonopsislacusalpinus6 Encyonopsislacusalpinus7
View image metadata

Description

Valves are elliptic-lanceolate and not or slightly dorsiventral. Apices are subcapitate. The axial area is narrow and a central area is lacking. The raphe is filiform. Proximal raphe ends are not expanded and deflected dorsally. Distal raphe fissures are hooked toward the ventral margin. Striae are parallel to weakly radiate, somewhat more prominent and more widely spaced near the valve center.

Autecology

Encyonopsis lacusalpini is known only from Upper Trilobite Lake, a small alpine lake on the Continental Divide in the heart of the Bob Marshall Wilderness of Montana (photo below). Water quality data are not available.

Trilobite Lake Mt 1
Credit: Loren Bahls
Upper Trilobite Lake, Bob Marshall Wilderness, Montana: type locality of Encyonopsis lacusalpini.

Original Description

Valves elliptic-lanceolate, not or slightly dorsiventral. Apices subcapitate. Valve length 11.3–12.6 µm; valve width 3.0–3.4 µm. Axial area narrow. Central area lacking. Raphe filiform. Proximal raphe ends not expanded, deflected dorsally. Distal raphe fissures hooked toward the ventral margin. Striae parallel to weakly radiate, somewhat more widely spaced near the valve center, 26–29 in 10 µm.

  • Author
    Bahls 2013
  • Length Range
    11.3-12.6 µm
  • Width
    3.0-3.4 µm
  • Striae in 10µm
    26-29

Original Images

Encyonopsis lacusalpini orig illus
Encyo Lacusalpini Origdesc002

Cite This Page

Bahls, L. (2013). Encyonopsis lacusalpini. In Diatoms of North America. Retrieved April 17, 2024, from https://diatoms.org/species/encyonopsis_lacusalpini

Responses

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