• Category
  • Diameter
    7-16 µm
  • Width Range
    10-16 µm
  • Striae in 10 µm
  • Synonyms
    Melosira valida (Grunow in Van Heurck) F.Meister



Frustules are cylindrical and form chains. Valves are 7-16 µm in diameter, with a mantle height of 7-16 µm. The ratio of the mantle height to valve diameter is 0.8-1.5. The mantle has thick walls. The valve face is slightly convex, covered by small areolae. Pervalvar rows of coarse, rectangular areolae are strongly curved to the right (dextrorse), 12-17 in 10 µm. There are 11-17 areolae in 10 µm along the pervalvar row. The mantle areolae are larger near the valve face and gradually become smaller toward the collum. The collum is approximately 1/3-1/5 of the mantle height. The spines are large, spatula-shaped and originate from two pervalvar costae. The ringleiste is solid and wide.

Original Description

  • Basionym
    Melosira crenulata var. valida
  • Author
    Grunow in Van Heurck 1882

Original Images

Melosira Crenulata Var Valida Orig Desc Plate

Cite This Page

English, J., Potapova, M. (2010). Aulacoseira valida. In Diatoms of North America. Retrieved May 28, 2024, from https://diatoms.org/species/aulacoseira_valida


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