Stauroneis pikuni | Species - Diatoms of North America

Category

Symmetric Biraphid
Length Range

53-64 µm
Width Range

9.0-12.0 µm
Striae in 10 µm

24-28

Reported As

Stauroneis gracilior "Zackenberg" (Van de Vijver et al. 2004)

Contributor

Loren Bahls - Dec 2011
Reviewer

Mark Edlund - Mar 2012

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Identification

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Description

Valves are lanceolate to rhombic-lanceolate with gradually narrowed capitate apices. Raphe branches are moderately lateral, becoming filiform at the distal and proximal ends. Proximal raphe ends are straight and not expanded. The axial area is narrow and linear, barely wider than the raphe, and expands slightly at the central area. The central area is a rectangular stauros. Striae are radiate throughout. Areolae are round to transapically oblong, irregularly spaced, and number 20-24 in 10 µm.

Autecology

Stauroneis pikuni is widely distributed in lakes and ponds throughout the Northern Rockies, but is rarely found in abundance. In waters where Stauroneis pikuni occurs, pH ranges from 6.6 to 7.3 and specific conductance ranges from 8 to 71 µS/cm. Van de Vijver et al. (2004) reported this taxon (as Stauroneis gracilior "Zackenberg") from the Zackenberg area of East Greenland.

Size Range, µm3

1001-10000
Motility

Moderately motile
Attachment

Unattached
Habitat

Benthic
Colony

Solitary
Waterbody

Inland
Learn more about this

Loren At Marinas Pond Glacier National Park

Credit: Marina Potapova

Loren Bahls at Two Medicine Campground Pond, Glacier National Park, Montana: type locality for Stauroneis pikuni.

Original Description

Valves lanceolate with gradually narrowed capitate to subcapitate ends. Length 53-64 µm, width 9-12 µm. Raphe fissures moderately lateral, becoming filiform at the distal and proximal ends. Proximal raphe endings straight, pores not inflated or deflected. Axial area narrow and linear, barely wider than the raphe, flaring slightly at the central area. Central area a narrow rectangular fascia. Striae radiate throughout, 24-28 in 10 µm. Striae puncta fine, round to oblong, and irregularly spaced, 20-24 in 10 µm. For measurements, n = 22 valves.

Author

Bahls 2010
Length Range

53-64 µm
Width

9-12 µm
Striae in 10µm

24-28

Original Images

Citations & Links

Citations

Cite This Page

Bahls, L. (2011). Stauroneis pikuni. In Diatoms of North America. Retrieved December 16, 2024, from https://diatoms.org/species/48038/stauroneis_pikuni

Responses

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