Diatoms of North AmericaDiatoms of North America

Gomphonema acuminatum

Ehrenb. 1832

Gomphonema Acuminatum Guide
  • Category
    Asymmetric Biraphid
  • Length Range
    19-77 µm
  • Width Range
    7-12 µm
  • Striae in 10 µm
    9-12 at the center, 12-14 towards the footpole

Identification

Gomphonema Acuminatum 002 Gomphonema Acuminatum 001 Gomphonema Acuminatum 003 Gomphonema Acuminatum 005 Acuminatum Gc109928B004 Gomphonema Acuminatum 004
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Description

Valves are clavate, tumid at the center with two constrictions along the margin; near the headpole the valve broadens and then becomes apiculate at the headpole, the footpole is rounded. The axial area is narrow, straight, until broadening to form an irregular central area. The central area bears a single stigma. The raphe is lateral and undulate. The external proximal raphe ends are dilated. The external distal raphe ends are deflected onto the mantle in the direction opposite the stigma. Striae are radiate, strongly so at the footpole. A bilobed apical pore field is present at the footpole. Septa and pseudosepta are present at the poles.

Original Description

  • Author
    Ehrenb. 1832

Original Images

Ehr 1832 G Acuminatum

Cite This Page

Kociolek, P. (2011). Gomphonema acuminatum. In Diatoms of North America. Retrieved November 21, 2024, from https://diatoms.org/species/gomphonema_acuminatum

Responses

The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Gomphonema acuminatum 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.