Navicula veneta

Kützing 1844      Category: Symmetrical biraphid
BASIONYM: Navicula veneta Kützing 1844
SYNONYM(S): Navicula cryptocephala var. veneta (Kützing) Rabenhorst 

Navicula venerablis

 

Navicula vilaplanii
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LM scalebar = 10 µm = 80 pixels.

Observations

Contributor: Marina Potapova - March 2011
Length Range: 17-26 µm
Width Range: 4.4-5.3 µm
Striae in 10 µm: 14-15 in the center valve

Description

Valves are lanceolate to linear-lanceolate with moderately protracted apices. The axial area is narrow and straight. The central area is transversely rectangular or ellipticl. The raphe is straight, with drop-like external proximal ends. Striae are slightly radiate around the center, becoming convergent at the apices. The areolae are sometimes visible under LM, approximately 35 in 10 μm.

Original Description

Basionym: Navicula veneta
Author: Kützing 1844
Length Range: 19.6 µm
Striae in 10 µm:

Original Description

N. minutula, lanceolata, latiuscula, laevissima, apicibus productis obtusiusculus. Long. 1/115’’’.

Original Images

Cite This Page:
Potapova, M. (2011). Navicula veneta . In Diatoms of the United States. Retrieved May 25, 2013, from http://westerndiatoms.colorado.edu/taxa/species/navicula_veneta

Species: Navicula veneta

Contributor: Marina Potapova

Reviewer: Sam Rushforth

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Image Credit: Marina Potapova

  1. Valves lanceolate to linear-lanceolate, with moderately protracted apices
  2. Central area transversely rectangular or elliptic
  3. External proximal raphe ends drop-like

Valves are lanceolate to linear-lanceolate with moderately protracted apices. The central area is transversely rectangular or elliptic. The raphe is straight, with drop-like external proximal ends. The striae are slightly radiate around the center, becoming convergent at the apices. The areolae are sometimes visible under LM, approximately 35 in 10 μm.

Compare

Navicula veneta differs from N. namibica by coarser striae and higher areola density. Navicula cryptocephala is larger, with more protracted ends and larger, circular central area.

Navicula cryptocephala

Navicula namibica

Lange-Bertalot and Rumrich

Citations

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

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

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Navicula veneta CAS

North American Diatom Ecological Database (NADED)

NADED ID: 46504

Autecology Discussion

Pollution-tolerant species

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 veneta

Distribution

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

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 veneta

Responses

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