Encyonema neogracile | Species - Diatoms of North America

Category

Asymmetric Biraphid
Length Range

18.7-41.3 µm
Width Range

5.5-6.7 µm
Striae in 10 µm

12-15

Synonyms

Encyonema gracile Rabenh. 1853
Reported As

Cymbella lunata (Patrick and Reimer 1975, p. 46, plate 7, figs. 11-14)
Cymbella gracilis (Krammer and Lange-Bertalot 1986, p. 308, fig. 120: 3-5)

Contributor

Loren Bahls - Jun 2016
Reviewer

Diane Winter - Jul 2016

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Identification

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Description

Valves are cymbelloid and narrow, with narrowly rounded apices. The dorsal margin is moderately arched. The ventral margin is weakly convex to nearly flat with a slightly tumid central valve. The central area is slightly wider than the axial area,. The raphe is lateral, narrowing near the proximal ends and terminal fissures. Proximal raphe ends are deflected dorsally and terminate in inconspicuous central pores. Distal raphe fissures are long and curved ventrally. Striae on the dorsal side are radiate and more widely separated at the valve center than near the apices. The median dorsal stria has a single isolated areola near the central area. The shorter striae on the ventral side are parallel to radiate near the valve center, becoming convergent near the apices. Areolae in the striae are fine and number 30-35 in 10 µm.

Autecology

Encyonema neogracile is widespread and common in lakes, fens and mossy seeps in the mountains of the Northwest United States. These waters typically have low concentrations of nutrients, low to very low electrical conductance, and circumneutral pH.

Size Range, µm3

101-1000
Motility

Slightly motile
Attachment

Tube-Forming
Habitat

Benthic
Colony

Colonies occasional
Waterbody

Inland
Distribution

Northeast lake sediments Great Lakes inventory
Learn more about this

Credit: Loren Bahls

Kootenai Pond, Glacier National Park, Montana: home of Encyonema vulgare

Original Description

Author

Krammer 1997
Length Range

16-50 µm
Width

5.5-6.6 µm
Striae in 10µm

12-14

Original Images

Citations & Links

Citations

Cite This Page

Bahls, L. (2016). Encyonema neogracile. In Diatoms of North America. Retrieved December 16, 2024, from https://diatoms.org/species/50328/encyonema_neogracile1

Responses

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