Amphora ovalis

(Kützing) Kützing 1844      Category: Asymmetrical biraphid
BASIONYM: Frustulia ovalis Kützing 1833
SYNONYM(S): Navicula amphora Ehrenberg 

Amphora minutissima

 

Amphora pediculus
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LM scalebar = 10 µm = 40 pixels.

Observations

Contributor: Joshua Stepanek | Pat Kociolek - January 2011
Length Range: 32-95 µm
Width Range: 8-17 µm
Striae in 10 µm: 10-12

Description

Valves are semi-elliptical with a smoothly arched dorsal margin and slightly concave ventral margin. Valve ends are rounded. The axial area is narrow. An uninterrupted raphe ledge (a thin, elevated T shaped structure that extends laterally to the raphe) is present. The raphe ledge is visible extending the length of the cell, covering the dorsal and ventral striae near the axial area. The raphe is linear and arched dorsally. Proximal and distal raphe ends are deflected dorsally. Dorsal striae are interrupted transapically by intercostal ribs and are slightly radiate centrally, becoming more radiate towards the apices. Ventral striae consist of an uninterrupted row of single areolae, slightly radiate centrally becoming convergent at the apices. A dorsal fascia is absent; a ventral fascia is present, extending to the ventral margin.

Original Description

Basionym: Frustulia ovalis
Author: Kützing 1833
Length Range: µm
Striae in 10 µm:

Original Description

Original Images

Cite This Page:
Stepanek, J., and Kociolek, P. (2011). Amphora ovalis. In Diatoms of the United States. Retrieved May 23, 2013, from http://westerndiatoms.colorado.edu/taxa/species/amphora_ovalis

Species: Amphora ovalis

Contributor: Joshua Stepanek | Pat Kociolek

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Image Credit: Josh Stepanek

  1. Dorsal fascia absent
  2. Proximal raphe ends dorsally deflected
  3. Raphe ledge distinct
  4. Dorsal striae interrupted by intercostal ribs
  5. Ventral striae uninterrupted

Valves semi-elliptical with smoothly arched dorsal margin and slightly concave ventral margin. An uninterrupted raphe ledge is present. The raphe ledge is visible extending the length of the cell, covering the dorsal and ventral striae near the axial area. Raphe arched with proximal and distal ends dorsally deflected. Striae interrupted dorsally by intercostal ribs, composed ventrally of a single row of areolae. Dorsal fascia absent, ventral fascia present and extending to the valve margin.

Compare

Amphora ovalis can be differentiated from A. copulata by the absence a clear dorsal fascia.

Amphora copulata

Citations

Krammer, K. (1980). Morphologic and taxonomic investigations of some freshwater species of the diatom genus Amphora Ehr. Bacillaria 3:197-225.

Kützing, F.T. (1844). Die kieselschaligen Bacillarien oder Diatomeen. Nordhausen. 152 pp., 30 pls.

Lee, K. and Round, F.E. (1987). Studies on freshwater Amphora species. I. Amphora ovalis. Diatom Research 2 (2): 193-203.

Schoeman, F.R. and Archibald, R.E.M. (1986). Observations on Amphora species (Bacillariophyceae) in the British Museum (Natural History). V. Some species from the subgenus Amphora. South African Journal of Botany. 53: 425-437.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Amphora ovalis CAS

North American Diatom Ecological Database (NADED)

NADED ID: 7001

Autecology Discussion

Habits

Size Range

1001-10,000 µm3 (ie Diatoma vulgaris)
10,001-100,000 µm3 (ie Cymbella tumida)

Motility

slightly motile (e.g. Cocconeis)

Attachment

prostrate (e.g. mucilage pad)

Habitat

benthic

Colony

EMAP Assessment

Sampling for 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). Streams and rivers in 12 western states (Arizona, California, Colorado, Idaho, Montana, Nevada, North Dakota, Oregon, South Dakota, Utah, Washington and Wyoming). Over 1200 sites on 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.

EMAP Distribution

Amphora ovalis

Distribution

The distribution map represents the relative abundance of this Amphora ovalis in the western EMAP study. Relative abundance is a measure of the proportion of cells of this species based on a "fixed count" of 300 total diatom cells counted and identified. Each of the western EMAP sample sites is shown, either with a black dot for sites where Amphora ovalis was not recorded, or with a red circle indicating the relative abundance of Amphora ovalis.

Note that the size of the proportional symbols varies between species to help show both abundant and rare species.

Scale for the map to the left

EMAP Response Plots

Amphora ovalis

Responses

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

EMAP citations

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.