Fallacia pygmaea
(Kützing) Stickle and Mann in Round et al. 1990 Category: Symmetrical biraphid
BASIONYM: Navicula pygmaea Kützing 1849
LM scalebar = 10 µm = 80 pixels.
Observations
Contributor: Pat Kociolek - March 2011
Length Range: 17-38 µm
Width Range: 8-13 µm
Striae in 10 µm: 24-28 in the center, more fine towards the apices, 32-34
Description
Valves are elliptical with rounded apices, not protracted. The axial area is narrow and straight. The raphe is straight and filiform. A lyre-shaped unornamented area bisects the striae on either side of the axial area, connecting to form the central area. The striae are radiate and finely punctate.
Original Description
Basionym: Navicula pygmaea
Author: Kützing 1849
Length Range: µm
Striae in 10 µm:
Original Description
Original Images
Cite This Page:
Kociolek, P. (2011). Fallacia pygmaea. In Diatoms of the United States. Retrieved May 23, 2013, from http://westerndiatoms.colorado.edu/taxa/species/fallacia_pygmaea
Species: Fallacia pygmaea
Contributor: Pat Kociolek
Reviewer: Rex Lowe
Image Credit: Pat Kociolek
- Valves broadly lanceolate
- Apices rounded
- Lyre-shaped hyaline area
- Striae finely punctate
Valves are broadly lanceolate with rounded apices. A lyre-shaped unornamented area bisects the striae on either side of the axial area, connecting to form the central area.
Compare
This species is larger, and has more finely punctate striae than F. tenera.
Pseudofallacia tenera
Citations
Patrick, R.M. and Reimer, C.W. (1966). The Diatoms of the United States exclusive of Alaska and Hawaii, V. 1. Monographs of the Academy of Natural Sciences of Philadelphia 13.
Round, F.E., Crawford, R.M. and Mann, D.G. (1990). The Diatoms. Biology and Morphology of the Genera. Cambridge University Press, Cambridge, 747 pp.
Links & ID's
Index Nominum Algarum (INA)
California Academy of Sciences (CAS)
North American Diatom Ecological Database (NADED)
NADED ID: 115001
Autecology Discussion
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
Fallacia pygmaea
Distribution
The distribution map represents the relative abundance of this Fallacia pygmaea 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 Fallacia pygmaea was not recorded, or with a red circle indicating the relative abundance of Fallacia pygmaea.
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
Fallacia pygmaea
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.