Encyonema montanum | Species - Diatoms of North America

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

Contributor

Loren Bahls - Dec 2018
Reviewer

Sarah Spaulding - Dec 2018

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Identification

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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.

Size Range, µm3

101-1000
Motility

Slightly motile
Attachment

Tube-Forming
Habitat

Benthic
Colony

Colonies occasional
Occurrence

Rare
Waterbody

Inland Rivers
Learn more about this

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

Citations & Links

Citations

Bahls, L.L. (2017) Diatoms from western North America 1. Some new and notable biraphid species. Helena, Montana: edited and published by the author. pp. [1]-52, 288 figs. ISBN-10: 0945345860 ISBN-13: 978-0945345862

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 December 26, 2024, from https://diatoms.org/species/94663/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.