Sellaphora rexii
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Category
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Length Range22-33 µm
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Width Range7.1-8.6 µm
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Striae in 10 µm20-24
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ContributorMarina Potapova - Dec 2010
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ReviewerSam Rushforth - Feb 2013
Identification
Description
Valves are elliptic with subrostrate apices. The axial area is linear, formed by grooves, one at each side of the raphe. Grooves are approximately 0.5 μm wide and covered externally by non-porous conopeum. Grooves and conopea are interrupted by the central area, which is transversely rectangular, or bow-tie-shaped and bordered by striae of an irregular length. The striae are uniseriate, radiate throughout most of the valve, but parallel or convergent near the apices. Near the valve ends, the striae are interrupted and internally form "polar bars", which are visible in LM. The areolae are small, rounded, approximately 50-55 in 10 μm. The raphe is straight, with expanded central endings.
Original Description
Valves are elliptical, with subrostrate apices. 22-33 μm long, 7.1-8.6 μm wide (Fig. 4). The axial area is straight, formed by grooves, one at each side of the raphe. Grooves are approximately 0.5 μm wide and covered externally by non-porous conopeum (Fig. 4E). Grooves and conopea are interrupted by the central area, which is transversely rectangular, or bow-tie-shaped and bordered by striae of an irregular length. The striae are uniseriate, radiate throughout most of the valve, but parallel or convergent near the apices, 20-24 in 10 μm. Near the valve ends, the striae are interrupted and internally form "polar bars" which are visible on LM photographs (Fig. 4A-D). The areolae are small, rounded, approximately 50-55 in 10 μm. The raphe is straight, with expanded central endings, and terminal fissures curved to the secondary side of the valve.
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AuthorPotapova and Ponader 2008
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Length Range22-33 µm
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Width7.1-8.6 µm
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Striae in 10µm20-24
Original Images
Cite This Page
Potapova, M. (2010). Sellaphora rexii. In Diatoms of North America. Retrieved December 16, 2024, from https://diatoms.org/species/45325/sellaphora_rexii
Responses
The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Sellaphora rexii 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.
Sellaphora rexii
- Valves elliptic with subrostrate apices
- Grooves along each side of raphe 0.5 μm wide
- Grooves covered by conopea
- Central area transversely rectangular or bow-tie shaped
Valves are elliptic, with subrostrate apices. Valves are 22-33 μm long and 7.1-8.6 μm wide. The axial area is linear, formed by grooves, one at each side of the raphe. Grooves are approximately 0.5 μm wide and covered externally by non-porous conopeum. Grooves and conopea are interrupted by the central area, which is transversely...