Eunotia orthohedra
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Category
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Length Range12-19 µm
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Width Range2.7-3.8 µm
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Striae in 10 µm16-20 in the valve center, 20-22 at the ends
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ContributorPaula Furey - Feb 2011
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ReviewerMarina Potapova - Mar 2011
Identification
Description
The ventral margin is slightly concave and has subapical swellings at the proximal raphe ends. The dorsal margin is flattened with angular shoulders subtending the apices. Valves are narrow, 4.2 – 6.0 times longer than wide. The apices are capitate, dorsally recurved, and rounded. Helictoglossae are not visible in the LM. One apical rimoportula. The raphe is short and curves on to the valve face. The striae are radiate and may be faint in appearance. The areolae are unresolved in the LM.
Autecology
Eunotia orthohedra is epilithic and epiphytic on bryophytes in wet walls, creeks, and waterfalls.
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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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Occurrence
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Waterbody
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Original Description
Valves slightly concave with subapical swellings on the ventral margin at the proximal raphe ends, flattened on the dorsal margin with angular shoulders subtending the apices, narrow, 4.2 – 6.0 times longer than wide, 12 – 19 μm long, 2.7 – 3.8 μm wide. Apices capitate, dorsally recurved, rounded. Helictoglossae not visible in the light microscope. Rimoportula at one end. Raphe short, curved on to valve face. Striae indistinct, radiate, 16 – 20 in 10 μm at the center of the valve, 20 – 22 in 10 μm near the ends. Puncta unresolved in light microscope.
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AuthorFurey, Lowe and Johansen 2011
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Length Range12-19 µm
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Width2.7-3.8 µm
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Striae in 10µm16-20 in the center valve, 20-22 at the ends.
Original Images
Cite This Page
Furey, P. (2011). Eunotia orthohedra. In Diatoms of North America. Retrieved December 21, 2024, from https://diatoms.org/species/45592/eunotia_orthohedra
Responses
The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Eunotia orthohedra 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.
Eunotia orthohedra
- Ventral margin with subapical swellings
- Dorsal margin straight
- Angular shoulders subtending the apices
- Apices capitate, dorsally recurved
- Striae indistinct, radiate
The ventral margin is slightly concave with subapical swellings at the proximal raphe ends. The dorsal margin is flattened with angular shoulders subtending the apices. Valves are narrow and 4.2 – 6.0 times longer than wide. The apices are capitate, dorsally recurved and rounded. The raphe is short and curves on to the valve face. The...