Halamphora oligotraphenta
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Category
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Length Range22-33 µm
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Width Range3.9-4.6 µm
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Striae in 10 µm26-30 in the center, 32-34 near the poles
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SynonymsAmphora veneta var. capitata E.Y.Haw. 1974
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ContributorJoshua Stepanek - Mar 2011
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ReviewerSam Rushforth - Aug 2013
Identification
Description
Valves are semi-lanceolate and strongly dorsiventral, with a smoothly arched dorsal margin and a weakly concave ventral margin. The ventral margin is often slightly tumid near the central portion. The valve ends are protracted and capitate. The raphe occurs near the ventral margin, is straight and gently deflects dorsally as it nears the central area. The proximal raphe ends are widely spaced; the distal ends are deflected dorsally. The axial area is narrow throughout. A dorsal and ventral fascia are both absent. Dorsal striae are punctate and radiate throughout. Ventral striae are continuous, although often difficult to observe in light microscope.
Original Description
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BasionymAmphora oligotraphenta
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AuthorLange-Bert. in Lange-Bert. and Metzeltin 1996
Original Images
Citations & Links
Citations
Links
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Index Nominum Algarum
Cite This Page
Stepanek, J. (2011). Halamphora oligotraphenta. In Diatoms of North America. Retrieved December 21, 2024, from https://diatoms.org/species/46142/halamphora_oligotraphenta
Responses
The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Halamphora oligotraphenta 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.
Halamphora oligotraphenta
- Valve ends protracted capitate
- Dorsal striae punctate
- Proximal raphe ends widely spaced
- Striae 26-30 near middle, 32-34 near poles
Valves are semi-lanceolate and strongly dorsiventral. Valve ends are protracted and capitate.The proximal ends are widely spaced. The axial area is narrow throughout. Dorsal and ventral fascia are absent. Dorsal striae are punctate and radiate throughout. Ventral striae are continuous.