Navicula capitatoradiata

Germain ex Gasse 1986      Category: Symmetrical biraphid
BASIONYM: Navicula cryptocephala var. intermedia Grunow in Van Heurck 1880

REPORTED AS: Navicula salinarum var. intermedia (Patrick and Reimer 1966) 

Navicula canalis

 

Navicula cari
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LM scalebar = 10 µm = 80 pixels.

Observations

Contributor: Sam Rushforth | Sarah Spaulding - November 2010
Length Range: 30-37 µm
Width Range: 7.0-7.7 µm
Striae in 10 µm: 14-15

Description

Valves are lanceolate, with protracted rostrate ends, 7.0-7.7 µm wide and 30-37 µm long. The raphe is filiform. The axial area is narrow and linear. The central area is oval to irregular, often with alternately long and short striae. Striae are radiate and curved, or irregularly curved near the valve center. Striae become convergent at the valve apices. Striae are lineolate, 14-15 in 10 µm.

Original Description

Basionym: Navicula cryptocephala var. intermedia
Author: Grunow in Van Heurck 1880
Length Range: µm
Striae in 10 µm:

Original Description

N. CRYPTOCEPHALA Kg. VAR INTERMEDIA (se rapprochant du N. salinarum).

Original Images

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

Species: Navicula capitatoradiata

Contributor: Sam Rushforth | Sarah Spaulding

Reviewer: Pat Kociolek

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Image Credit: Sarah Spaulding

  1. Ends distinctly protracted, rostrate
  2. Striae irregular and curved at valve center
  3. Central area oval to irregular, often with alternately long and short striae

Valves are lanceolate with distinctly protracted, rostrate ends.

Compare

Navicula capitatoradiata has very distinct protracted, rostrate ends while N. oligotraphenta has weakly protracted rounded ends. Navicula capitatoradiata also has more convergent striae near the poles.

Navicula oligotraphenta

Lange-Bertalot et Hofmann

Citations

Cox, E.J. (1995). Taxonomic studies on the diatom genus Navicula Bory VII. The identity and typification of Navicula gregaria Donkin, N. cryptocephala Kutz. and related taxa. Diatom Research 10: 91-111.

Gasse, F. (1986). East African diatoms: Taxonomy, ecological distribution . Bibliotheca Diatomologica, Vol: 11, 201 pp.

Germain, H. (1981). Flore des diatomées - Diatomophycées- eaux douces et saumâtres du Massif Armoricain et des contrées voisines d'Europe occidentale. Collection "Faunes et Flores Actuelles". Société Nouvelle des Editions Boubée, Paris. 444 pp.

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)

Transfer INA

California Academy of Sciences (CAS)

Navicula capitatoradiata CAS

North American Diatom Ecological Database (NADED)

NADED ID: 46661

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 capitatoradiata

Distribution

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

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 capitatoradiata

Responses

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