Rexlowea navicularis
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Category
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Length Range44–132 µm
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Width Range18–30 µm
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Striae in 10 µm5–6 in the center, 20 at the apices
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SynonymsAmphiprora navicularis Ehrenb. 1843
Placoneis navicularis (Ehrenb.) E.J.Cox 2003
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ContributorPat Kociolek - Mar 2011
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ReviewerSam Rushforth - Oct 2011
Identification
Description
Valves are broadly lanceolate, with apices protracted to broadly rounded. The axial area is narrow and straight, forming a narrow, linear to ovoid central area. The raphe is lateral and undulate, with large, rounded external proximal ends and hooked external distal ends. Striae are radiate, with the 1st or 2nd stria at each apex parallel or, rarely, convergent. Within a stria, the marginal areola are large and coarsely arranged. The middle portion has areola comparatively smaller and rounded, and the areolae near the axial area form two rows per stria. The central area has large, round, isolated puncta. The smallest striae at the apices are multiseriate throughout their length.
Original Description
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BasionymNavicula semen
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AuthorEhrenb. 1841
Citations & Links
Citations
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Publication Link: 10.1046/j.1095-8339.2003.00115.x
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Publication Link: 10.1127/0029-5035/2010/0090-0195
Links
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Index Nominum Algarum
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North American Diatom Ecological DatabaseNADED ID: 93028
Cite This Page
Kociolek, P. (2011). Rexlowea navicularis. In Diatoms of North America. Retrieved December 21, 2024, from https://diatoms.org/species/46176/rexlowea_navicularis1
Responses
The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Rexlowea navicularis 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.
Rexlowea navicularis
- Apices protracted to broadly rounded
- Proximal raphe ends large, rounded
- Central area with isolated puncta
- Raphe lateral
- Raphe undulate
Valves are broadly lanceolate with apices protracted to broadly rounded. The raphe is lateral and undulate. Within a stria, the marginal areolae are large and more coarsely arranged. The middle valve has areolae comparatively smaller and rounded. Central area has large, round isolated puncta. The smallest striae at the apices are...