Frustulia saxonica

Rabenhorst 1850      Category: Symmetrical biraphid
BASIONYM: Frustulia saxonica Rabenhorst 1853

Frustulia rexii

 

Frustulia soror
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LM scalebar = 10 µm = 40 pixels.

Observations

Contributor: Pat Kociolek | Carrie Graeff - January 2011
Length Range: 46.5-87.5 µm
Width Range: 12.5-17.5 µm
Striae in 10 µm: 30-33

Description

Valves are generally rhomboid in shape, although valves at the small end of the size range are not strongly rhomboid. The apices are slightly constricted and narrowly rounded. The longitudinal ribs are slightly curved. Both the thickness of the ribs and size of the central nodule are variable in relation to valve size. The porte-crayon is relatively small. Striae are radiate the apices. Longitudinal striae are present, but may be disorganized at the valve center.

Original Description

Basionym: Frustulia saxonica
Author: Rabenhorst 1853
Length Range: µm
Striae in 10 µm:

Original Description

Original Images

Cite This Page:
Kociolek, P., and Graeff, C. (2011). Frustulia saxonica. In Diatoms of the United States. Retrieved July 31, 2014, from http://westerndiatoms.colorado.edu/taxa/species/frustulia_saxonica

Species: Frustulia saxonica

Contributor: Pat Kociolek | Carrie Graeff

Reviewer: Sarah Spaulding

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Image Credit: Carrie Graeff

  1. Valve shape variable
  2. Apices slightly constricted
  3. Porte-crayon relatively small

The degree of rhomboid valve shape is variable within populations, in direct proportion to valve size. The apices are slightly constricted and a relatively small porte-crayon is present.

Compare

Frustulia saxonica is generally less robust than F. rexii, with finer valves, more narrowly rounded apices, thinner longitudinal ribs and a smaller porte-crayon. Frustulia saxonica has much more narrowly rounded apices than F. quadrisinuata, and its margins are not undulate, as the margins of F. quadrisinuata. The striae of F. saxonica are radiate at the apices, while the striae of F. krammeri and F. inculta are not radiate. Frustulia saxonica has a much higher stria density than that of F. krammeri (24-26 in 10 microns). Frustulia saxonica has relatively shorter helictoglossae than F. inculta, so that the porte-crayon appears smaller in F. saxonica.

Frustulia rexii

Frustulia quadrisinuata

Frustulia krammeri

Frustulia inculta

Citations

Lange-Bertalot, H. (2001). Navicula sensu stricto, 10 genera separated from Navicula sensu lato, Frustulia. Diatoms of Europe 2: 1-526.

Rabenhorst, L. (1848). Die Algen Sachsens. Resp. Mittel-Europa’s Gesammelt und herausgegeben von Dr. L. Rabenhorst, Dec. 1-100. No. 1-1000. Dresden. [Exsiccata, issued at various dates]. Dec. 1-100. No. 1-1000. Dresden. [Exsiccata, issued at various dates].

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Frustulia saxonica CAS

North American Diatom Ecological Database (NADED)

NADED ID: 35025

Autecology Discussion

Habits

Size Range

1001-10,000 µm3 (ie Diatoma vulgaris)

Motility

moderately motile (e.g. Navicula tripunctata)

Attachment

other (e.g. tubes or thallose)

Habitat

benthic

Colony

occasional colony

EMAP Assessment

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.

EMAP Distribution

Frustulia saxonica

Distribution

The distribution map represents the relative abundance of this Frustulia saxonica 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 Frustulia saxonica was not recorded, or with a red circle indicating the relative abundance of Frustulia saxonica.

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

Frustulia saxonica

Responses

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