Credit: Barb Johnston, Parks Canada
Blakiston Beaver Pond A, Waterton Lakes National Park, Alberta: type locality for Stauroneis ancepsfallax.
Stauroneis ancepsfallax
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Category
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Length Range52-70 µm
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Width Range11.4-14.2 µm
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Striae in 10 µm17-23
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Reported AsStauroneis (?nov.) spec. (Werum and Lange-Bertalot, 2004, Pl.50, Fig. 4)
Stauroneis spec. cf. amphicephala Kützing (Lange-Bertalot and Genkal, 1999, Tafel 31, Fig. 8)
Stauroneis (?nov.) spec. 2 Julma Olkky cf. anceps (Lange-Bertalot and Metzeltin, 1996, Tafel 32, Figs 5-6)
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ContributorLoren Bahls - Dec 2011
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ReviewerSarah Spaulding - Aug 2013
Identification
Description
Valves are lanceolate with capitate apices. The axial area is narrow and nearly linear, widening slightly near the stauros. The stauros is shaped like a bow tie and is strongly expanded near the valve margins. External raphe fissures are moderately lateral. Proximal raphe ends are nearly straight. The proximal raphe pores are small and only slightly expanded. Striae are radiate throughout. Areolae are fine and number 22-26 in 10 µm.
Autecology
Stauroneis ancepsfallax has been collected from several ponds and small lakes in the Northern Rockies. These waters have circumneutral pH (range 6.7-8.6) and low to moderate specific conductance (range 22-250 µS/cm). An unidentified taxon with similar features was reported from Siberia (Lange-Bertalot & Genkal 1999), from an oligo-dystrophic lake in Finland (Lange-Bertalot & Metzeltin 1996), and from springs in central Europe (Werum & Lange-Bertalot 2004).
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Size Range, µm3
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Motility
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Attachment
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Habitat
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Colony
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Waterbody
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Original Description
Valves lanceolate with capitate ends. Length 52-70 µm, width 11.4-14.2 µm. Axial area narrow, nearly linear, widening slightly near the central area. Central area shaped like a bow tie, strongly expanded toward valve margins. Raphe fissures moderately lateral, proximal endings nearly straight, weakly deflected to the secondary side. Central pores small, only slightly inflated. Striae radiate throughout, 17-23 in 10 µm. Striae puncta fine, 22-26 in 10 µm. For measurements, n = 14 valves.
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AuthorBahls 2010
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Length Range52-70 µm
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Width11.4-14.2 µm
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Striae in 10µm17-23
Original Images
Citations & Links
Citations
Links
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Index Nominum Algarum
Cite This Page
Bahls, L. (2011). Stauroneis ancepsfallax. In Diatoms of North America. Retrieved December 21, 2024, from https://diatoms.org/species/47680/stauroneis_ancepsfallax
Responses
The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Stauroneis ancepsfallax 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.
Stauroneis ancepsfallax
- Apices capitate
- Valves lanceolate
- Stauros bow tie shaped
- Proximal raphe ends straight, weakly expanded
Stauroneis ancepsfallax has lanceolate valves with capitate apices. The valves are 11-14 µm wide. The stauros is distinctly expanded toward the valve margins and shaped like a bow tie. Proximal raphe ends are nearly straight and weakly expanded.