Nitzschia recta

Hantzsch ex Rabenhorst 1862      Category: Nitzschioid
SYNONYM(S): Nitzschia vitrea var. recta (Hantzsch in Rabenhorst; Grunow in Cleve and Grunow) Van Heruck 

Nitzschia perminuta

 

Nitzschia regula var. robusta
Show images Hide

LM scalebar = 10 µm = 40 pixels.

Observations

Contributor: Kalina Manoylov - June 2010
Length Range: 48-85 µm
Width Range: 4.7-7 µm
Striae in 10 µm: 39-50

Description

Frustules are rectangular in girdle view. Valves are flat, linear to linear-lanceolate, with wedge-shaped ends. Apices are beak-like, rounded, and somewhat rostrate. The raphe is positioned at the valve margin. A conopeum is visible sometimes in LM. Striae are visible in large specimens. Fibulae are long (1-2 µm) and irregularly spaced, 6-8 in 10 µm.

Cite This Page:
Manoylov, K. (2010). Nitzschia recta. In Diatoms of the United States. Retrieved May 22, 2013, from http://westerndiatoms.colorado.edu/taxa/species/nitzschia_recta

Species: Nitzschia recta

Contributor: Kalina Manoylov

Reviewer: Marina Potapova

Show guide Hide

Image Credit: Kalina Manoylov

  1. Apices beak-like
  2. Valves > 40 µm in length
  3. Striae fine

Valves are linear to linear-lanceolate with beak-like apices. Valve length is greater than 40 µm. Valve ends are rostrate. Striae are fine and may be visible in LM only in larger specimens. Fibulae are perpendicular to the margin and irregularly spaced.

Compare

Nitzschia recta is lanceolate and less robust than N. rectirobusta, which is wider and has coarser striae. Nitzschia recta has long fibulae and the conopeum may be visible in some specimens, features that distinguish it from N. dissipata var media.

Nitzschia dissipata var. media

Nitzschia rectirobusta

Lange-Bertalot

Citations

Rabenhorst, L. (1862). Die Algen Europa’s. Decas 129-130.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Nitzschia recta CAS

North American Diatom Ecological Database (NADED)

NADED ID: 48029

Autecology Discussion

Habits

Size Range

10,001-100,000 µm3 (ie Cymbella tumida)

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

Nitzschia recta

Distribution

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

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

Nitzschia recta

Responses

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