Gomphoneis mammilla
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Category
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Length Range95-271 µm
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Width Range25-45 µm
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Striae in 10 µm7-9
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SynonymsGomphoneis mamilla (Ehrenb.) Cleve 1894
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ContributorPat Kociolek - Feb 2011
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ReviewerSam Rushforth - Jul 2011
Identification
Description
Valves are distinctly clavate in shape. The headpole is either subrostrate, or broadly rounded. The footpole is broadly rounded. The axial area is relatively narrow, straight, widening only slightly to form a narrowly elliptical central area. A single stigma is present in the central area. The raphe is lateral and weakly undulate. The external distal raphe ends are deflected at the poles onto the mantle, in the direction opposite the side bearing the stigma. External proximal raphe ends are dilated. Striae are distinctly biseriate, radiate throughout the length of the valve. Longitudinal lines are evident on either side of the axial area, positioned 1/5-1/4 of the way between the valve margin and the axial area. Two conspicuous spines are present at the headpole. The footpole bears distinct apical pore fields. Septa and pseudosepta are present at the apices.
Distribution: Gomphoneis mammilla has been verified from the west coast and at higher elevations in the Rocky Mountains of the U.S.
Original Description
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BasionymGomphonema mammilla
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AuthorEhrenb. 1854
Citations & Links
Citations
Links
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Index Nominum Algarum
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North American Diatom Ecological DatabaseNADED ID: 36008
Cite This Page
Kociolek, P. (2011). Gomphoneis mammilla. In Diatoms of North America. Retrieved December 16, 2024, from https://diatoms.org/species/45675/gomphoneis_mammilla
Responses
The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Gomphoneis mammilla 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.
Gomphoneis mammilla
- Valves distinctly clavate
- Striae 7-9 in 10 µm
- Headpole subrostrate to broadly rounded
- Two spines at the headpole
Valves are distinctly clavate in shape. The axial area is relatively narrow, straight, widening only slightly to form a narrowly elliptical central area with a single stigma. The raphe is lateral, weakly undulate. External proximal raphe ends are dilated. Striae are evidently doubly-punctate, radiate the length of the valve. Longitudinal...