Diatoms of North AmericaDiatoms of North America

Gomphonema eileencoxiae

(Bahls) Bahls, Wetzel and Ector 2018

Gomphonema Eileencoxiae Guide
  • Category
    Asymmetric Biraphid
  • Length Range
    59.5-94.3 µm
  • Width Range
    8.2-10.7 µm
  • Striae in 10 µm
    7-9 at valve center, 10-13 at the ends
  • Synonyms
    Kurtkrammeria eileencoxiae Bahls 2015

Identification

Kurtkrammeria Coxiae 459301 0 Kurtkrammeria Coxiae 459301 1 Kurtkrammeria Coxiae 459301 2 Kurtkrammeria Coxiae 459301 3 Kurtkrammeria Coxiae 459401 4 Kurtkrammeria Coxiae 459301 5 Kurtkrammeria Coxiae 459401 6
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Description

Valves are rhombic-lanceolate, slightly dorsiventral, or cymbelloid, and nearly isopolar. Apices are narrowly rounded and somewhat apiculate. The axial area is narrow and widens gradually toward a transversely rectangular central area. The raphe is lateral, becoming filiform at the proximal and distal ends. External proximal raphe ends are weakly inflated and deflected dorsally. Distal raphe fissures are comma-shaped, and concave toward the ventral margin. Striae are radiate throughout. Areolae number 26-30 in 10 µm. A single stigmoid lies at the proximal end of the median stria on the dorsal side. On the ventral side of the central area is one very short stria.

This posting of Gomphonema eileencoxiae on the Diatoms of North America website is in celebration of Dr. Eileen Cox's 70th birthday. This species was initially described as Kurtkrammeria eileencoxiae Bahls 2015 without benefit of SEM images. When the SEM images were obtained, they showed well-developed apical pore fields at one end of the valve, which is consistent with the genus Gomphonema, rather than Kurtkrammeria.

Autecology

This taxon is known only from two small ponds near the Continental Divide in southwestern Montana (photos below). Specific conductance in the ponds ranged from 21-25 μS/cm and pH ranged from 6.54-7.43.

Bloody Dick Pond 1
Credit: Loren Bahls
Bloody Dick Pond No. 1, Beaverhead County, Montana: type locality of Gomphonema eileencoxiae.
Bloody Dick Pond 2
Credit: Loren Bahls
Bloody Dick Pond No. 2, Beaverhead County, Montana: home of Gomphonema eileencoxiae.

Original Description

Valves are rhombic-lanceolate and slightly dorsiventral (cymbelloid). Apices are narrowly rounded, somewhat apiculate. Valve length 60-94 μm; valve width 8.2-10.7 μm. The axial area is narrow and widens gradually towards a transversely rectangular central area. The raphe is lateral, becoming filiform at the proximal and distal ends. External proximal raphe ends are weakly inflated and deflected dorsally. Distal raphe fissures are comma-shaped, and concave towards the ventral margin. Striae are parallel to weakly radiate over most of the valve, becoming more strongly radiate very near the apices. Striae number 7-9 in 10 μm at valve center, 10-13 in 10 μm near the apices. Areolae number 26-30 in 10 μm. A single stigma lies at the proximal end of the median stria on the dorsal side. On the ventral side of the central area is one very short stria. [n=30]

  • Basionym
    Kurtkrammeria eileencoxiae
  • Author
    Bahls 2017
  • Length Range
    60-94 µm
  • Width
    8.2-10.7 µm
  • Striae in 10µm
    7-9 in the valve center, 10-13 near the apices

Original Images

Gomphonema Eileencoxiae
Figs1 8 Gomphonema Eileencoxiae Sem
Figs9 14 Gomphonema Eileencoxiae Sem

Cite This Page

Bahls, L. (2018). Gomphonema eileencoxiae. In Diatoms of North America. Retrieved November 21, 2024, from https://diatoms.org/species/gomphonema_eileencoxiae

Responses

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