• Category
  • Diameter
    9.8-23.1 µm
  • Striae in 10 µm
    16-19 near valve margin



The valve face is flat, the mantle slopes to the valve margin. Striae are composed of coarse areolae. Striae are radial and straight, but not organized into fascicles. Some striae extend from the valve margin to the center, while others extend only partially to the center. Marginal fultoportulae number 7-27 per valve, spaced 2-3 µm between between one another. Rimoportulae number 1-3 per valve. Internal extensions of the rimoportulae are of the same height as the fultoportulae. Areolae number 18-21 in 10 µm within a stria. The central areolae are often 3-6 times the size of other areolae.


Planktonic in mildly eutrophic lakes and reservoirs.

Original Description

Frustules 9-25 µm in diameter. Initial valves hemispherical, without evident processes on the exterior surface or visible processes in LM (Figs. 1-2, 17), but marginal fultoportulae and rimportula visible in internal view (Fig. 18), 22-25 µm in diameter. Vegetative valve face flat, with mantle sloping to the margin (Figs. 19-20). Marginal fultoportulae 7-27 per valve, with 2-3 µm between adjacent fultoportulae (Figs. 4, 7, 9, 11, 15). Rimoportulae number 1 to 3 per valve (Figs. 4, 7, 9, 11, 15), with internal extensions at the same height as the fultoportulae (Figs 18, 21-24). Striae radial, straight, some extending from the margin to the center, others extending only partially to center (Figs. 3-16), 16-19 in 10 µm. Areolae 18-21 in10 µm within striae, with central areolae often 3-6 times the size of other areolae (Figs. 3, 13, 19, 20).

  • Author
    J.R.Johansen, Kociolek and R.L.Lowe 2008
  • Length Range
    9-25 µm
  • Striae in 10µm

Original Images

Spic Holo

Cite This Page

Lowe, R. (2015). Spicaticribra kingstonii. In Diatoms of North America. Retrieved July 22, 2018, from https://diatoms.org/species/spicaticribra_kingstonii


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