Denticula tenuis

Kützing 1844      Category: Nitzschioid
BASIONYM: Denticula tenuis Kützing 1844

Decussata placenta

 

Diadesmis confervacea
Show images Hide

LM scalebar = 10 µm = 80 pixels.

Observations

Contributor: Pat Kociolek - March 2011
Length Range: 12-20 µm
Width Range: 4 µm
Striae in 10 µm: 22-28

Description

Valves are lanceolate to elliptical-lanceolate, with protracted apices. The raphe is distinct, positioned off center and contained within a canal. Transapical costae are distinct. The striae are punctate. Included in this concept is D. tenuis var. crassula (Naeg. ex Kützing) W. & G.S. West, which appears to represent valves at the lower size range of D. tenuis.

Specimens we have encountered occupy a narrow size range. Patrick and Reimer (1966) give the size range as 6-60 µm long, 3-7 µm broad. Found in alkaline waters across the United States.

Original Description

Basionym: Denticula tenuis
Author: Kützing 1844
Length Range: µm
Striae in 10 µm:

Original Description

  1. DENTICULA TENUIS. Taf. 17. Fig. VIII. 420/1 D. anguste linearis, margine subtiliter punctata, latere secundario subtiliter striato, anguste lan¬ceolato ; striis transversalibus in 1/100"' Parte 10-11. Bacillaria palea Nitzsch. Taf. 3. Fig. 3.? Unter Conferven und andern Diatomeen in fliessenden und stehenden Wassergräben bei Nordhausen ! theils einzeln, theils in grössern Haufen beisammen. - Länge bis 1/90‘‘‘. Anmerk. Diese Form hat so grosse Aehnlichkeit mit den einzelnen Gliedern des Diatoma tenue (Taf. 17. Fig. X.), dass ich sie anfangs von diesen nicht verschieden gehalten habe. Später fand ich dieselbe aber sehr häufig immer wieder in diesem losen Zustande, lebend und in Bewegung, wie die Naviculae, und dies hat mich veranlasst, sie hier als besondere Art aufzuführen.

Original Images

Cite This Page:
Kociolek, P. (2011). Denticula tenuis. In Diatoms of the United States. Retrieved May 20, 2013, from http://westerndiatoms.colorado.edu/taxa/species/denticula_tenuis

Species: Denticula tenuis

Contributor: Pat Kociolek

Reviewer: Mark Edlund

Show guide Hide

Image Credit: Pat Kociolek

  1. Valves lanceolate to elliptic-lanceolate
  2. Protracted apices
  3. Costae distinct
  4. Raphe eccentric

Valves lanceolate to elliptic-lanceolate, with protracted apices. The raphe is distinct, positioned off center and contained within a canal. Costae are distinct and number 5-7 in 10 µm.

Compare

This species is distinguished from others in the genus by the raphe being only slightly eccentrically placed and the lanceolate shape of the valve.

Citations

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

Links & ID's

Index Nominum Algarum (INA)

INA

California Academy of Sciences (CAS)

Denticula tenuis CAS

North American Diatom Ecological Database (NADED)

NADED ID: 25002

Autecology Discussion

Habits

Size Range

101-1000 µm3 (ie Amphora veneta)

Motility

moderately motile (e.g. Navicula tripunctata)

Attachment

prostrate (e.g. mucilage pad)

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

Denticula tenuis

Distribution

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

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

Denticula tenuis

Responses

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