Navicula caterva

Hohn and Hellerman 1963      Category: Symmetrical biraphid
BASIONYM: Navicula caterva Hohn and Hellerman 1963

Navicula caroliniae

 

Navicula cincta
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LM scalebar = 10 µm = 80 pixels.

Observations

Contributor: Mark Edlund | Marina Potapova | Sarah Spaulding - July 2010
Length Range: 14.8-20.0 µm
Width Range: 4.4-5.0 µm
Striae in 10 µm: 18-20

Description

Valves are lanceolate with subrostrate ends. Striae are radiate at the valve center, becoming parallel to slightly divergent at the ends. Central striae may be bent with shortened striae enclosed by longer neighboring striae. The central area is small and transapically oval to rectangular in shape, occupying about 1/3 of the valve breadth.

Original Description

Basionym: Navicula caterva
Author: Hohn and Hellerman 1963
Length Range: 10.4-16.6 µm
Width Range: 4.2-5.2 µm
Striae in 10 µm: 16-18

Original Description

Valva lanceolata, apicibus subrostratis leniter. Longitudo 10.4-16.6 µ. Latitudo 4.2-5.2 µ. Striis latis, punctatis obscure, radiates ad mediampartem, paralelis ad apices 16-18/10 µ. Area axiali lineari. Raphe tenui, directa. Area media parva, rectangulari transapicaliter.

Valve lanceolate, ends slightly subrostrate; length 10.4-16.6 µ, width 4.2-5.2 µ striae broad, indistinctly punctuate, radiate at center, parallel at ends 16-18/10 µ; axial area linear; raphe thin, straight; central area small, transapically rectangular.

Occasionally the center pair of striae are more shortened than illustrated and are enclosed by the adjacent striae.

This species is similar in size and shape to Navicula perparva Hust. (Arch. Hydrobiol. Suppl., 15: 246, pl. 20, figs 16-18, 1937) but differs in that the striae, particularly those at the ends, are coarse and parallel. In N. perparva the striae become quite fine at the ends and are radiate.

Specimen illustrated: GC. 44466, Type. Type locality: Potomac River, Md. Distribution: Type locality and Ridley Creek, Pa.

Original Images

Cite This Page:
Edlund, M., Potapova, M., and Spaulding, S. (2010). Navicula caterva. In Diatoms of the United States. Retrieved May 22, 2013, from http://westerndiatoms.colorado.edu/taxa/species/navicula_caterva

Species: Navicula caterva

Contributor: Mark Edlund | Marina Potapova | Sarah Spaulding

Reviewer: Rex Lowe

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Image Credit: Marina Potapova

  1. Valves lanceolate with nearly blunt to subrostrate ends
  2. Central area small
  3. Striae radiate in the center valve
  4. Striae 18-20 in 10 µm

Valves are lanceolate with protracted, subrostrate ends. The central area is small. Striae are radiate in center and parallel to slightly convergent at the apices, 18-20 in 10 µm. Striae may be bent in the middle of the valve. Short striae may alternate with longer ones around the central area.

Compare

Navicula reichardtiana has relatively broader valves with coarser striae than N. caterva. The stria density is greater in N. caterva (18 in 10 µm) than in N. reichardtiana (14-16 in 10 µm).

Navicula reichardtiana

Citations

Hohn, M.H. and Hellerman, J. (1963). The taxonomy and structure of diatom populations from three Eastern North American rivers using three sampling methods. Transactions of the American Microscopical Society 82(3):250-329.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Navicula caterva CAS

North American Diatom Ecological Database (NADED)

NADED ID: 46646

Autecology Discussion

Habits

Size Range

11-100 µm3 (ie Achnanthidium)

Motility

moderately motile (e.g. Navicula tripunctata)

Attachment

Habitat

benthic

Colony

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 caterva

Distribution

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

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 caterva

Responses

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