Diatoms of North AmericaDiatoms of North America

Stauroneis sacajaweae

Bahls 2012

Stauroneis Sacajawea Guide
  • Category
    Symmetric Biraphid
  • Length Range
    54-80 µm
  • Width Range
    10.8-14.7 µm
  • Striae in 10 µm
    23-25
  • Reported As
    Stauroneis subhyperborea (Bahls 2010, p. 155, figs. 1-8)

Identification

Stauroneis sacajaweae LM6 Stauroneis sacajaweae LM5 Stauroneis sacajaweae LM4 Stauroneis sacajaweae LM3 Stauroneis sacajaweae LM2 Stauroneis sacajaweae LM1
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Description

Valves are lanceolate with gradually attenuated subrostrate apices. A deep pseudoseptum occupies each apex. The raphe is lateral, becoming filiform towards proximal ends, which are bent to one side and tipped with weakly inflated pores. Distal raphe ends are hooked in a direction opposite that of proximal ends. The axial area is about 3 times wider than the raphe and widens gradually towards central area. The central stauros is broad and shaped like a bow tie. Striae are strongly radiate throughout. Areolae number 18–22 in 10 μm.

Autecology

Stauroneis sacajaweae has been confirmed from only two localities, both headwater spring seeps at moderate elevations in the northern Rocky Mountains of Montana.

Square Butte 1
Credit: Loren Bahls
Round Butte (left) and Square Butte (right) near Geraldine in Chouteau County, Montana. A spring seep at the base of Square Butte is the type locality for Stauroneis sacajaweae.

Original Description

Valves lanceolate with gradually attenuated subrostrate apices. A deep pseudoseptum occupies each apex (Fig. 15). Valve length 54–80 μm; valve width 10.8–14.7 μm. Raphe lateral, becoming filiform towards proximal ends, which are bent to one side and tipped with weakly inflated pores. Distal raphe ends hooked in a direction opposite that of proximal ends. Axial area c 3 x wider than raphe and widens gradually towards central area. Central stauros broad, shaped like a bow tie. Striae strongly radiate throughout, 23–25 in 10 μm. Areolae in striae 18–22 in 10 μm.

  • Author
    Bahls 2012
  • Length Range
    54-80 µm
  • Width
    10.8-14.7 µm
  • Striae in 10µm
    23-25

Original Images

Staurossacaja Origdimag
Staurossacaja Origdesc

Cite This Page

Bahls, L. (2012). Stauroneis sacajaweae. In Diatoms of North America. Retrieved November 21, 2024, from https://diatoms.org/species/stauroneis_sacajaweae

Responses

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