Diatoms of North AmericaDiatoms of North America

Encyonema montanum

Bahls 2017

Encyonema Montana Guide
  • Category
    Asymmetric Biraphid
  • Length Range
    15.8-22.4 µm
  • Width Range
    6.8-8.5 µm
  • Striae in 10 µm
    11-12
  • Synonyms
    Encyonema montanum Bahls

Identification

Encyonema montana LM1 Encyonema montana LM3 Encyonema montana LM2 Encyonema montana LM4 Encyonema montana LM6 Encyonema montana LM5 Encyonema montana LM7
View image metadata Type

Description

Valves are almost semicircular with a strongly arched dorsal margin and a weakly convex ventral margin. The axial area is narrow and a central area is absent. The raphe is filiform. External proximal raphe ends are weakly expanded and deflected dorsally. Terminal raphe fissures are deflected ventrally. Dorsal striae are radiate; ventral striae are parallel or weakly radiate. Areolae number 28-36 in 10 μm.

Autecology

The type locality and the only record to date of this taxon is Wolf Creek, a prairie stream in eastern Montana. On the date of sampling, Wolf Creek had a specific conductance of 1181 μS/cm and a pH of 8.74. This is a small species considered within the Encyonema reimeri group from the western United States.

Encyonema reimeri Sensu Lato Copy
Credit: Loren Bahls
Taxa in the Encyonema reimeri group from the western United States.

Original Description

Valves are almost semicircular with a strongly arched dorsal margin and a weakly convex ventral margin. Valve length 16-22 μm; valve width 6.8-8.5 μm. The axial area is narrow and a central area is absent. The raphe is filiform. External proximal raphe ends are weakly expanded and deflected dorsally. Terminal raphe fissures are deflected ventrally. Dorsal striae are radiate; ventral striae are parallel or weakly radiate. Striae number 11-12 in 10 μm. Areolae number 28-36 in 10 μm.

  • Basionym
    Encyonema montanum ('montana')
  • Author
    Bahls 2017
  • Length Range
    15.8-22.4 µm
  • Width
    6.8-8.5 µm
  • Striae in 10µm
    11-12

Original Images

Encyonema Montana Bahls 2017

Updates

Nov 04, 2024 - Correction of specific epithet

From 12/26/2018 until 11/4/2024, this taxon appeared as Encyonema montana Bahls 2017. To conform with the neutral gender of Encyonema, the ending is corrected to "montanum". - S. Spaulding

Cite This Page

Bahls, L. (2018). Encyonema montanum. In Diatoms of North America. Retrieved November 13, 2024, from https://diatoms.org/species/encyonema-montanum

Responses

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