Epithemia adnata

(Kützing) Brébisson 1838      Category: Epithemioid
BASIONYM: Frustulia adnata Kützing 1833

Entomoneis punctulata

 

Epithemia reicheltii
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LM scalebar = 10 µm = 40 pixels.

Observations

Contributor: Rex Lowe - December 2010
Length Range: 32-70 µm
Width Range: 7.5-9.7 µm
Striae in 10 µm: 12-14

Description

Valves are dorsiventral and are 32-70 μm long and 7.5-9.7 μm wide. Valves taper toward rounded to rostrate ends. Striae are 12-14 in 10 μm and costae are 4-5 in 10 μm. There are 3-7 striae between costae. The dorsal margin is strongly convex and the ventral margin is moderately concave. The raphe canal lies against the ventral margin at distal ends of the valve and arches toward the dorsal margin in the valve center. The central arch of the canal is approximately 3-6 μm above the ventral margin reaching less than half the distance to the dorsal margin.

Original Description

Basionym: Frustulia adnata
Author: Kützing 1833
Length Range: µm
Striae in 10 µm:

Original Description

Frustulis adnatis fuscis crassiusculis cymbiformibus opacis, saepe hyalino-marginatis, media interdum fascia transversali hyalina notatis, utrinque truncatis, plerumque binatim conjunctis.

Original Images

Cite This Page:
Lowe, R. (2010). Epithemia adnata. In Diatoms of the United States. Retrieved May 24, 2013, from http://westerndiatoms.colorado.edu/taxa/species/epithemia_adnata

Species: Epithemia adnata

Contributor: Rex Lowe

Reviewer: Sarah Spaulding

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Image Credit: Rex Lowe

  1. Striae 12-14 in 10 μm
  2. Costae 3-4 in 10 μm
  3. Raphe canal lies against ventral margin at distal ends of valve arching toward the dorsal margin in valve center
  4. Central arch of canal approximately 3-6 μm above the ventral margin reaching less than half the distance to the dorsal margin

Valves are dorsiventral, with rounded to rostrate ends. Striae 12-14 in 10 μm, costae are 3-4 in 10 μm with 3-7 striae between costae. Dorsal margin is strongly convex and ventral margin is moderately concave. Raphe canal lies against the ventral margin at distal ends of the valve arching toward the dorsal margin in valve center. The central arch of the canal is approximately 3-6 μm above the ventral margin reaching less than half the distance to the dorsal margin.

Compare

Epithemia adnata has finer striae (12-14 in 10 μm) than E. turgida (8-10 in 10 μm). In addition, E. adnata has 3-7 striae between adjacent costae, while E. turgida has 2-3 striae between adjacent costae. The valves of E. reichelti are more triangular in shape and the raphe canal is positioned on the dorsal margin.

Epithemia turgida

Epithemia reicheltii

Citations

Brébisson, A. de. (1838). Considérations sur les Diatomées et essai d'une classification des genres et des espèces appartenant à cette famille. Brée l'Ainé Imprimeur-Libraire, Falaise. 22 pp.

Krammer, K. and Lange-Bertalot, H. (1988). Bacillariophyceae. 2. Teil: Bacillariaceae, Epithemiaceae, Surirellaceae. In: Ettl, H., J. Gerloff, H. Heynig and D. Mollenhauer (eds.) Susswasserflora von Mitteleuropa, Band 2/2. Gustav Fisher Verlag, Jena.

Kützing, F.T. (1833). Synopsis Diatomacearum oder Versuch einer systematischen Zusammenstellung der Diatomeen. Linnaea 8(5): 529-620, pls. XIII-XIX.

Links & ID's

Index Nominum Algarum (INA)

California Academy of Sciences (CAS)

Epithemia adnata CAS

North American Diatom Ecological Database (NADED)

NADED ID: 32003

Autecology Discussion

This taxon is often in aggregates in areas of low N/P ratio. Often epiphytic. Like other species of Epithemia, E. adnata contains endosymbiotic N-fixing cyanobacteria.

Habits

Size Range

1001-10,000 µm3 (ie Diatoma vulgaris)

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

Epithemia adnata

Distribution

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

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

Epithemia adnata

Responses

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