• Category
  • Length Range
    35-70 µm
  • Width Range
    7.4-11.5 µm
  • Striae in 10 µm



Valves are linear-lanceolate to linear, with abruptly protracted subrostrate to subcapitate apices. External raphe fissures are weakly lateral. Proximal raphe ends are slightly curved and tipped with weakly expanded central pores. The axial area is narrow and linear, barely wider near the central area. The central area is a relatively broad stauros that is somewhat wider near the valve margins. Short striae are absent within in the stauros. Striae are weakly radiate near the center, becoming more strongly radiate toward the apices. Areolae are distinguishable in LM and number 20-30 in 10 µm.


Stauroneis acidoclinata has been recorded from several ponds and small lakes in western Montana, including Glacier National Park, where pH is circumneutral (mean pH = 6.8) and specific conductance is very low (mean SC = 35 µS/cm).

Bloody  Dick  Pond 1
Credit: Loren Bahls
Bloody Dick Pond No. 1, Beaverhead County, Montana: home of Kurtkrammeria coxiae.

Original Description

Schalen linear-lanzettlich bis linear, Enden ziemlich abrupt keilformig verschmalert, meistens breit rostrat vorgezogen und breit gerundet, niemals capitat or subcapitat. Lange 35-60 microns, Breite 8.5-10.5 microns. Innere und aussere Raphenspalten (nicht stark) lateral, Zentralporen (im LM undeutlich) seitlich abgekrummt. Axialarea annahernd linear, weder eng noch breit, zur Mitte etwas erweitert. Zentralarea als Stauros bis zu den Randern ausgedehnt und nur wenig erweitert. Streifen im mittleren Schalenteil massig, zu den Enden hin stark radial, 21-23/10 microns. Punkte auf den Streifen (im REM) transapikal verlangert, ca. 25-30/10 microns.

  • Author
    Lange-Bert. and Werum 2004
  • Length Range
    35-60 µm
  • Width
    8.5-10.5 µm
  • Striae in 10µm

Original Images

Sacidoclinata Origimag
Sacidoclinata Origdesc

Cite This Page

Bahls, L. (2011). Stauroneis acidoclinata. In Diatoms of North America. Retrieved June 23, 2018, from https://diatoms.org/species/stauroneis_acidoclinata


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