Identification

Description

Valves are linear and weakly dorsiventral, with triundulate or slightly concave dorsal and ventral margins. Apices are subrostrate and deflected ventrally. The axial area is narrow. The central area is rounded and asymmetric, about one half the valve width. The raphe is lateral, becoming filiform near the proximal and distal ends. Proximal raphe ends are weakly inflated and deflected dorsally. Distal raphe fissures are very prominent, comma-shaped, and concave toward the ventral side. Striae are radiate throughout.

Autecology

Encyonopsis lacuscaerulei was collected from the benthos of two lower elevation lakes in northwest Montana. Here pH measured 8.0 and 8.3 and specific conductance measured 350 and 230 µS/cm.

Savage  Lake
Credit: Loren Bahls
Savage Lake, Lincoln County, Montana: paratype locality of Encyonopsis lacuscaerulei.

Original Description

Valves linear, not or slightly dorsiventral, triundulate or with slightly concave dorsal and ventral margins. Apices subrostrate, deflected ventrally. Valve length 36–61 µm; valve width 5.5–6.8 µm. Axial area narrow. Central area rounded, asymmetric, about one half the valve width. Raphe lateral, filiform near the proximal and distal ends. Proximal raphe ends weakly inflated, deflected dorsally. Distal raphe fissures very prominent, comma-shaped, concave toward the ventral side. Striae radiate throughout, 17–20 in 10 µm.

  • Author
    L.L.Bahls 2013
  • Length Range
    36-61 µm
  • Width
    5.5-6.8 µm
  • Striae in 10µm
    17-20

Original Images

Encyonopsis lacuscaerulei orig illus
Encyo Lacuscaerulei Origdesc001

Cite This Page

Bahls, L. (2013). Encyonopsis lacuscaerulei. In Diatoms of North America. Retrieved July 21, 2018, from https://diatoms.org/species/encyonopsis_lacuscaerulei

Responses

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