Kociolek and Stoermer 1991 Category: Asymmetrical biraphid
BASIONYM: Gomphoneis geitleri Kociolek and Stoermer 1991
Valves are clavate, with a broadly rounded to subrostrate headpole. The footpole is narrow and rounded. The axial area is narrow. The central area may be transverse or round and contains a single stigma. The raphe is slightly undulate and lateral. Distinct helictoglossae are present near both apices. The striae are radiate near the central area, becoming nearly parallel near the valve ends. One to two striae distal to the helictoglossae are radiate. Some striae near the central area are irregular and shortened. An apical pore field is present at the footpole.
In the SEM, the valve exterior is covered with round areolae, organized into multiseriate striae. The striae are doubly punctate, to triply punctate near the axial area. Externally, the proximal raphe ends are straight. At the headpole, the distal raphe fissure is straight; at the footpole, the distal raphe fissure extends over the mantle and bisects the apical pore field. The stigma has a simple, round external opening. The apical pore field is composed of small, round porelli. Internally, a reduced pseudoseptum is present at the headpole. The striae are located in depressed chambers; an axial plate and marginal lamella are both absent. The proximal raphe ends are recurved at the central nodule. The internal expression of the stigma is multichambered. Distally, the raphe terminates at distinct helictoglossae. The apical pore field has depressed chambers.
The specimens presented here represent the range of one population - large initial valves to valves smallest end of the size range.
Basionym: Gomphoneis geitleri
Author: Kociolek and Stoermer 1991
Length Range: 17-45 µm
Width Range: 5-8 µm
Striae in 10 µm: 13-16
Valves are lanceolate to linear-lanceolate, with a capitate headpole and narrow footpole. The axial area is narrow, with a straight raphe. The central area is variable, orbicular to rectangular, and has a single isolated punctum. Striae number 13-16 in 10 µm and are radiate at the central area, strongly radiate at the footpole and nearly parallel at the headpole. Length 17-45 µm, breadth 5-8 µm.
Cite This Page:
Pickett, F., and Spaulding, S. (2011). Gomphoneis geitleri. In Diatoms of the United States. Retrieved July 06, 2015, from http://westerndiatoms.colorado.edu/taxa/species/gomphoneis_geitleri
Species: Gomphoneis geitleri
Reviewer: Pat Kociolek
Gomphoneis geitleri examined for this study was collected from 17 samples from five sites on Soda Butte Creek, Montana in 1972 and 1973. The stream is high elevation (2290 m.), moderate flow (2.5 cms mean flow), cold (0-10 °C), alkaline (pH 7.5-8.5), soft (26-74 mg/l CaCO3), well oxygenated (8.6-11 mg/l DO), and low to moderate nutrient content (0-0.05 mg/l NO3+NO2 and 0.02-0.06 µm/l PO4). Groundwater running through an abandoned gold and silver mine tailings pile leached reduced (Fe+2) iron into the stream 2.4 km above the sample point. Dilution from a relatively large tributary reduced the concentration of total iron at the sample point to 0.5-5.0 mg/l total Fe.
Confluence of Soda Butte Creek and Woody Creek, Montana, where Gomphoneis geitleri grows in high abundance. Image taken August 2011.
Credit/Source: Frank Pickett
The Environmental Protection Agency (EPA) western Environmental Monitoring and Assessment Program (EMAP) study was completed during the years 2000-2004 (see citations at bottom of this page). Over 1200 streams and rivers in 12 western states (Arizona, California, Colorado, Idaho, Montana, Nevada, North Dakota, Oregon, South Dakota, Utah, Washington and Wyoming) were selected for sampling based on a stratified randomized design. This type of design insures that ecological resources are sampled in proportion to their actual geographical presence. Stratified randomized design also allows for estimates of stream length with a known confidence in several “condition classes” (good or least-disturbed, intermediately-disturbed, and poor or most-disturbed) for biotic condition, chemistry and habitat.
Results are published in:
Johnson, T., Hermann, K., Spaulding, S., Beyea, B., Theel, C., Sada, R., Bollman, W., Bowman, J., Larsen, A., Vining, K., Ostermiller, J., Petersen, D. Hargett, E. and Zumberge, J. (2009). An ecological assessment of USEPA Region 8 streams and rivers. U.S. Environmental Protection Agency Region 8 Report, 178 p.
Stoddard, J. L., Peck, D. V., Olsen, A. R., Larsen, D. P., Van Sickle, J., Hawkins, C. P., Hughes, R. M., Whittier, T. R., Lomnicky, G. A., Herlihy, A. T., Kaufman, P. R., Peterson, S. A., Ringold, P. L., Paulsen, S. G., and Blair, R. (2005). Environmental Monitoring and Assessment Program (EMAP) western streams and rivers statistical summary. U.S. Environmental Protection Agency Report 620/R-05/006, 1,762 p.
Stoddard, J. L., Peck, D. V., Paulsen, S. G., Van Sickle, J., Hawkins, C. P., Herlihy, A. T., Hughes, R. M., Kaufman, P. R., Larsen, D. P., Lomnicky, G. A., Olsen, A. R., Peterson, S. A., Ringold, P. L., and Whittier, T. R. (2005). An ecological assessment of western streams and rivers. U.S. Environmental Protection Agency Report 620/R-05/005, 49 p.