Navicula antonii

Lange-Bertalot 2000      Category: Symmetrical biraphid
BASIONYM: Navicula menisculus var. grunowii Lange-Bertalot 1993

Navicula angusta

 

Navicula aurora
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LM scalebar = 10 µm = 80 pixels.

Observations

Contributor: Sam Rushforth | Sarah Spaulding - November 2010
Length Range: 11.5-16 µm
Width Range: 4.2-4.7 µm
Striae in 10 µm: 16-22

Description

Valves are lanceolate, 4.2-4.7 µm wide and 11.5-16 µm long. The raphe is filiform. The axial area is narrow and linear. The central area is relatively small, oval to slightly asymmetrical. Striae are radiate and curved near the valve center. Striae become convergent at the valve apices. Striae are lineolate, 16-22 in 10 µm. Lineolae 45-52 in 10 µm.

Note that lineolate striae are not evident in specimens from Utah streams illustrated here. We have, however, observed lineolate striae in other North American populations. Lineolate striae are also clearly evident in the light micrographs of the type material of Lange-Bertalot though the lineolae in the SEM of a specimen from the type material exceed resolution of the LM. The variation in lineolate striae is a topic that deserves further investigation.

Original Description

Basionym: Navicula menisculus var. grunowii
Author: Lange-Bertalot 1993
Length Range: 11-25 µm
Width Range: 6-7.5 µm
Striae in 10 µm: 10.5-15

Original Description

Var. menisculus et var. upsaliensis quoad structuras item ad instar similis sed distinguenda individuis semper valde minoribus, striis et lineolis densius positis. Valvae late lanceolatae apicibus (modice) obtuse rotundatis (sicut alterae varietates) sed longitudo 11-25 (usque ad 30?) um, latitudo circiter 6-7.5 um. Striae transapicales 10.5-15 in 10 um, lineolae cirticer 28-32 in 10 um.

Original Images

Cite This Page:
Rushforth, S., and Spaulding, S. (2010). Navicula antonii. In Diatoms of the United States. Retrieved June 19, 2013, from http://westerndiatoms.colorado.edu/taxa/species/navicula_antonii

Species: Navicula antonii

Contributor: Sam Rushforth | Sarah Spaulding

Reviewer: Pat Kociolek

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Image Credit: Sarah Spaulding

  1. Valve lanceolate
  2. Axial area narrow
  3. Central area small, irregular to oval
  4. Striae radiate and curved at midvalve, becoming parallel or convergent near poles

Navicula antonii is characterized by its lanceolate shape and curved striae. The axial area is narrow, widening only slightly at the central area. The central area is often irregular but may be distinctly ovate.

Compare

Navicula antonii is generally smaller and finer than N. menisculus. Several varieties of the latter exist that must be carefully separated from N. antonii. Navicula reichardtiana is linear-lanceolate with rostrate ends. Navicula veneta is more linear-rhombic in shape with somewhat drawn-out rostrate ends.

Navicula menisculus

Schumann

Navicula reichardtiana

Lange-Bertalot

Navicula veneta

Kützing

Citations

Lange-Bertalot, H. and Metzeltin, D. (1996). Indicators of oligotrophy - 800 taxa representative of three ecologically distinct lake types, Carbonate buffered - Oligodystrophic - Weakly buffered soft water. Lange-Bertalot, H. (ed.), Iconographia Diatomologica. Annotated Diatom Micrographs. Vol. 2. Ecology, Diversity, Taxonomy. Koeltz Scientific Books. Königstein, Germany, 2:390 pp.

Rumrich, U., Lange-Bertalot, H. and Rumrich, M. (2000). Diatoms of the Andes. From Venezuela to Patagonia/Tierra del Fuego and two additional contributions. Lange-Bertalot, H. (ed.), Iconographia Diatomologica. Annotated Diatom Micrographs. Vol. 9. Phytogeography-Diversity-Taxonomy. Koeltz Scientific Books, Königstein, Germany, 9:673 pp.

Links & ID's

Index Nominum Algarum (INA)

Transfer INA

California Academy of Sciences (CAS)

Navicula antonii CAS

North American Diatom Ecological Database (NADED)

NADED ID: 46893

Autecology Discussion

Images

Navicula antonii may dominate streams with little human impact in the western United States.

Credit/Source: Sam Rushforth

Habits

Size Range

101-1000 µm3 (ie Amphora veneta)

Motility

moderately motile (e.g. Navicula tripunctata)

Attachment

unattached

Habitat

benthic

Colony

solitary

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

Navicula antonii

Distribution

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

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

Navicula antonii

Responses

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