Craticula halophila

     Category: Symmetrical biraphid
BASIONYM: Navicula cuspidata var. halophila Grunow in Van Heurck 1885

REPORTED AS: Navicula halophila (Patrick and Reimer 1966, p. 467, plate 44, fig. 4) 

Craticula cuspidata

 

Craticula johnstoniae
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LM scalebar = 10 µm = 80 pixels.

Observations

Contributor: Loren Bahls - October 2012
Length Range: 33-52 µm
Width Range: 8.7-12.4 µm
Striae in 10 µm: 17-19

Description

Valves are rhombic lanceolate with acute apices, or very subtly protracted apices in small specimens. The axial area is very narrow. The central area is small and elliptic in shape. The raphe is filiform with straight, weakly expanded proximal ends and distal ends that are hooked to the same side. Striae are parallel to weakly radiate at the valve center, becoming convergent towards the apices. Areolae are fine and difficult to resolve in LM.

Original Description

Basionym: Navicula cuspidata var. halophila
Author: Grunow in Van Heurck 1885
Length Range: µm
Striae in 10 µm:

Original Description

var. halophila Grun. (Atl. Suppl. fig. 30.— in Type Ν° 12.) Etroit, très-petit : environ 5 c.d.m. ; stries délicates, 16 environ en 1 c.d.m., radiantes vers la partie moyenne, convergentes aux extrémités. Saumâtre. — Blankenberghe.

Original Images

Cite This Page:
Bahls, L. (2012). Craticula halophila. In Diatoms of the United States. Retrieved March 03, 2015, from http://westerndiatoms.colorado.edu/taxa/species/craticula_halophila_sensu_llb

Species: Craticula halophila

Contributor: Loren Bahls

Reviewer: Sarah Spaulding

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Image Credit: Loren Bahls

  1. Valves rhombic lanceolate
  2. Maximum width >10 µm
  3. Apices acute

Craticula halophila has rhombic lanceolate valves with acute apices. The maximum valve width is greater than 10 µm.

Compare

Craticula buderi has elliptic-lanceolate valves with short, rostrate apices and a maximum valve width of less than 10 µm.

Craticula buderi

Citations

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

Patrick, R.M. and Reimer, C.W. (1966). The Diatoms of the United States exclusive of Alaska and Hawaii, V. 1. Monographs of the Academy of Natural Sciences of Philadelphia 13.

Links & ID's

Index Nominum Algarum (INA)

Transfer INA

California Academy of Sciences (CAS)

Craticula halophila CAS

North American Diatom Ecological Database (NADED)

NADED ID: 21005

Autecology Discussion

Craticula halophila is widely distributed in streams acros the Northwestern Great Plains, where it prefers waters with high levels of dissolved solids (Montana Diatom Collection). There are 50 confirmed records of this taxon in the Montana Diatom Collection.

Habits

Size Range

1001-10,000 µm3 (ie Diatoma vulgaris)

Motility

moderately motile (e.g. Navicula tripunctata)

Attachment

unattached

Habitat

benthic

Colony

solitary

EMAP Assessment

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). Over 1200 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

Craticula halophila

Distribution

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

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

Craticula halophila

Responses

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

 

August 27, 2014 - Note page for Craticula buderi

The name, Craticula halophila, was originally applied to the specimens currently shown on the page for C. buderi. That page was revised and this page was opened. - S. Spaulding