• Category
  • Length Range
    39.4-65.1 µm
  • Width Range
    9.0-11.4 µm
  • Striae in 10 µm
    18-20

Identification

Description

Valves are linear with weakly convex, nearly parallel margins. Apices are cuneate to subrostrate and broadly rounded. The axial area is narrow and widens gradually toward the valve center, where it merges with a small rhomboidal central area. The raphe is filiform, with slightly expanded proximal ends that are deflected toward the secondary side. Distal raphe fissures are curved towards the same side as the proximal raphe ends. Striae are radiate at the valve center, becoming parallel and finally convergent near the apices. Areolae in the striae are very fine. A wide hyaline longitudinal line runs along the valve margin from apex to apex.

Autecology

Neidiopsis weilandii has been recorded from a small alpine lake in Washington (2060 m a.s.l.), from a small subalpine lake in Glacier National Park, Montana (1341 m a.s.l.), and from the marshy tributary of another subalpine lake in northwest Montana (1700 m a.s.l.). Water chemistry at the Washington locality is unknown but the lake probably has circumneutral pH and low concentrations of nutrients and dissolved solids. The pH of the lake in Glacier National Park was 8.3 and the specific conductance was 112μS cm−1. The marshy tributary of the subalpine lake in northwest Montana had a pH of 8.5 and a specific conductance of 181 μS cm−1.

Lake  Edna 2
Credit: Craig Weiland
Lake Edna, Wenatchee National Forest, Chelan County, Washington: Type locality for Neidiopsis weilandii.

Original Description

Valves are linear with weakly convex, nearly parallel margins. Valve length 39.4–65.1μm, valve width 9.0–11.4μm. Apices are cuneate to subrostrate and broadly rounded. The axial area is narrow and widens gradually towards the valve center where it merges with a small rhomboidal central area. The raphe is filiform with slightly expanded proximal ends that are bent toward the secondary side. Distal raphe fissures are curved toward the same side, as are the proximal raphe ends. Striae are radiate at the valve center, becoming parallel and finally convergent near the apices. Stria density 18–20 in 10μm; areolae in the striae are very fine. A wide hyaline line runs along the valve margin from apex to apex. Plastids were not observed.

  • Author
    L.L.Bahls 2014
  • Length Range
    39.4-65.1 µm
  • Width
    9.0-11.4 µm
  • Striae in 10µm
    18-20

Original Images

Neidiopsis  Bahls  Figures 30 43
Neidiopsis  Bahls  Figures 44 47
Neidiopsis  Bahls  Figures 48 51

Cite This Page

Bahls, L. (2015). Neidiopsis weilandii. In Diatoms of North America. Retrieved July 18, 2018, from https://diatoms.org/species/neidiopsis_weilandii

Responses

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