• Category
  • Diameter
    4-11 µm
  • Width Range
    4-7 µm
  • Striae in 10 µm
  • Synonyms
    Aulacoseira distans var. nivaloides (Camburn) E.Y.Haw.
    Melosira distans var. nivaloides Camburn in Camburn and Kingston



Frustules are cylindrical and form short chains. Valves are 4-11 µm in diameter, with a mantle height of 4-7 µm. The ratio of the mantle height to valve diameter is close to 1. The mantle has straight sides and the valve face is convex or concave. Rows of pervalvar areolae are straight or slightly inclined to the right (dextrorse), 14-22 in 10 µm, with 13-21 areolae in 10 μm. The height of the collum is approximately 1/3 of the mantle height. The valve face is covered by areolae. The spines are pointed and narrow, and originate from every second or third costa. The base of the spines tends to point out away from the valve face before curving upwards to become parallel to the pervalvar axis. The ringleiste is very shallow.


Original Description

Frustules rectangular in girdle view. Valve discshaped and distinctly convex or concave, 4.0-9.0 (11.0) μm in diameter. Valve face punctate. Striae on valve mantle are parallel to the pervalvar axis, striae 14-17 in 10 μm. Each stria composed of (3) 4-7 elongate puncta, puncta 13-15 in 10 μm. A row of spines occurs around the circumference of the valve face, spines 8-10 in 10 μm.

  • Basionym
    Melosira distans var. nivaloides
  • Author
    Camburn in Camburn & Kingston 1986
  • Length Range
    4-11 µm
  • Striae in 10µm

Original Images

Melosira distans var. nivaloides orig illus
Melosira distans var. nivaloides orig illus

Cite This Page

Potapova, M., English, J. (2010). Aulacoseira nivaloides. In Diatoms of North America. Retrieved June 13, 2024, from https://diatoms.org/species/aulacoseira_nivaloides


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