Navicula radiosa

Kützing 1844      Category: Symmetrical biraphid
BASIONYM: Navicula radiosa Kützing 1844

Navicula pseudolanceolata

 

Navicula recens
Show images Hide

LM scalebar = 10 µm = 40 pixels.

Observations

Contributor: Marina Potapova - March 2011
Length Range: 52-105 µm
Width Range: 8.8-11.2 µm
Striae in 10 µm: 9-11

Description

The valves are narrow and lanceolate, with acutely rounded ends. The axial area is narrow and linear. The central area is rhombic. The raphe is straight with proximal ends that are hooked to the secondary side. The transapical striae are strongly radiate, bent in the valve center and convergent near the poles. Lineolae number 28-32 in 10 μm.

Note that this concept of N. radiosa is similar to that of Lange-Bertalot (2001) and includes considerable morphological variation, especially in the overall shape of the valve and in the shape of the apices. Further investigations may reveal pseudocryptic species within N. radiosa.

Original Description

Basionym: Navicula radiosa
Author: Kützing 1844
Length Range: 75 µm
Striae in 10 µm: 6.6-8.0

Original Description

  1. NAVICULA RADIOSA. Taf. 4. Fig. XXIIl, (420/1). N. mediocris lanceolata, gracilίs, acuta, striis radiantibus distinctis, in 1/100’’’15-18. Long.1/30‘‘‘ In Süsswassergräben bei Halle! Weissenfels ! Nordhausen! — Die Streifen sind stärker und deutlicher als bei N. gracilis, der sie übrigens sehr ähnlich ist.

Original Images

Cite This Page:
Potapova, M. (2011). Navicula radiosa . In Diatoms of the United States. Retrieved May 21, 2013, from http://westerndiatoms.colorado.edu/taxa/species/navicula_radiosa

Species: Navicula radiosa

Contributor: Marina Potapova

Reviewer: Sarah Spaulding

Show guide Hide

Image Credit: Marina Potapova

  1. Valves narrow lanceolate
  2. Valves 8.8-11.2 μm wide
  3. Apices acutely rounded
  4. Central area rhombic
  5. Central striae strongly radiate

The valves are narrow and lanceolate with acutely rounded ends. The central area is rhombic. The striae are strongly radiate. Striae are bent in the valve center and convergent near the poles. Lineolae number 28-32 in 10 μm.

Compare

Navicula radiosa is easily distinguished from other Navicula species by the relatively large size and narrow, lanceolate valves.

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 radiosa CAS

North American Diatom Ecological Database (NADED)

NADED ID:

Autecology Discussion

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 radiosa

Distribution

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

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 radiosa

Responses

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