Diatoms of North AmericaDiatoms of North America

Encyonema paucistriatum

(A.Cleve) D.G.Mann 1990

Encyonema Paucistriatum Guide
  • Category
    Asymmetric Biraphid
  • Length Range
    25.0-38.8 µm
  • Width Range
    4.9-6.1 µm
  • Striae in 10 µm
    8-11
  • Reported As
    Cymbella paucistriata (Krammer and Lange-Bertalot 1986, p. 305, plate 119, figs 14-16)

Identification

Encyonema paucistriatum LM1 Encyonema paucistriatum LM2 Encyonema paucistriatum LM4 Encyonema paucistriatum LM3 Encyonema paucistriatum LM5 Encyonema paucistriatum LM6 Encyonema paucistriatum LM7
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Description

Valves are lunate with rounded apices. The dorsal margin is moderately arched. The ventral margin is flat to slightly tumid. The axial area is narrow. The central area is very small and asymmetric, formed by a slight shortening of the median dorsal stria. Raphe branches are straight, with proximal ends deflected to the dorsal side. Distal raphe fissures are curved ventrally. Striae on the dorsal side are slightly radiate and more widely separated at the valve center than they are near the apices. Specimens are variable in stria density; some valves have irregularly spaced striae. Striae on the ventral side are short, and more or less parallel throughout. Areolae in the striae are fine.

Autecology

The specimens shown on this web page were collected from wetland habitats on the tundra in Nunavut, Canada (photos below). These wetlands have circumneutral pH, low conductivity, and low concentrations of bioavailable nutrients. This species was described from material collected in Finnish Lapland (Cleve-Euler 1934) and has also been reported from oligotrophic waters in northern Sweden and the European Alps (Krammer and Lange-Bertalot 1986).

Sample 685601 Wetland Pool Near Baillie River
Credit: Beverly Boynton, Adventurers and Scientists for Conservation
Wetland pool near Baillie River, Nunavut, Canada: home of Encyonema paucistriatum
Sample 685601 Closeup Of Wetland Pool Near Baillie River
Credit: Beverly Boynton, Adventurers and Scientists for Conservation
Closeup of wetland pool near Baillie River, Nunavut, Canada. The reddish color is caused by precipitated iron hydroxide.
Sample 685701 Wet Hummocks Near Baillie River
Credit: Beverly Boynton, Adventurers and Scientists for Conservation
Wet hummocks near Baillie River, Nunavut, Canada: home of Encyonema paucistriatum

Original Description

  • Basionym
    Cymbella paucistriata
  • Author
    A.Cleve 1934
  • Length Range
    30-35 µm
  • Width
    6-7 µm
  • Striae in 10µm
    7-8

Original Images

Cymbella paucistriata orig illus
Encyonema Paucistriatum Origdesc001

Cite This Page

Bahls, L. (2016). Encyonema paucistriatum. In Diatoms of North America. Retrieved October 30, 2024, from https://diatoms.org/species/encyonema_paucistriatum

Responses

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