Planothidium frequentissimum

(Lange-Bertalot in Krammer and Lange-Bertalot) Lange-Bertalot 1999      Category: Monoraphid
BASIONYM: Achnanthes lanceolata subsp. frequentissima Lange-Bertalot 1993

Planothidium dubium

 

Planothidium haynaldii
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LM scalebar = 10 µm = 80 pixels.

Observations

Contributor: Marina Potapova - December 2010
Length Range: 5-17 µm
Width Range: 3-6 µm
Striae in 10 µm: 13-18

Description

Valves are lanceolate to elliptical with rounded or slightly drawn-out apices. The raphe valve has a linear axial area and central area that is variable in shape - from transversely rectangular to elliptical. The rapheless valve has a linear-lanceolate axial area that slightly widens in the center. The asymmetrical central area on rapheless valve contains a hood on the internal valve surface. The raphe is straight, with expanded external proximal endings. Terminal raphe fissures are curved to the secondary side of the valve . The striae are multiseriate and radiate throughout both valves.

Original Description

Basionym: Achnanthes lanceolata subsp. frequentissima
Author: Lange-Bertalot 1993
Length Range: 4-36 µm
Width Range: 2.5-6.5 µm
Striae in 10 µm:

Original Description

Valvae ellipticae finibus plerumque non protractis obtuse ad late rotundatis nonnumquam paulo protractis numquam abrupte rostrato-protractis. Longitudo 4-36 μm, latitude 2,5-6,5 μm. Raphovalva ab Achnanthes lanceolata ssp. lanceolata non differt. Areovalva nunc autem differt constructione particulare »cavum tectum« dictum nec »sinus« i.e. caverna aperta. Itaque ssp. frequentissima singulari complexione signorum typicorum est distinguenda subspeciebus lanceolata, rostrata, dubia, biporoma, robusta, apiculata, lanceolatoides

Original Images

Cite This Page:
Potapova, M. (2010). Planothidium frequentissimum. In Diatoms of the United States. Retrieved May 24, 2013, from http://westerndiatoms.colorado.edu/taxa/species/planothidium_frequentissimum

Species: Planothidium frequentissimum

Contributor: Marina Potapova

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Image Credit: Marina Potapova

  1. Valves lanceolate to elliptical with rounded or slightly drawn-out apices
  2. Valves 3-6 μm wide
  3. Rapheless valve with a hood

Valves are lanceolate to elliptical with rounded or slightly drawn-out apices, 5-17 μm long and 3-6 μm wide. The rapheless valve has a linear-lanceolate axial area that slightly widens in the middle. The asymmetrical central area on rapheless valve contains a hood on the internal valve surface.

Compare

Planothidium frequentissimum differs from other Planothidium species with a hood, such as P. biporomum and P. rostratum, by the lanceolate to elliptical valves with rounded or slightly drawn-out apices. The raphe valves of lanceolate shape may not be distinguishable from those of P. lanceolatum. The rapheless valves, however, of P. frequentissimum possess a hood – a feature not found in P. lanceolatum.

Planothidium rostratum

Planothidium biporomum

Planothidium lanceolatum

Citations

Lange-Bertalot, H. (1993). 85 Neue taxa und uber 100 weitere neu definierte Taxa erganzend zur Subwasserflora von Mittleuropa. Bibliotheca Diatomologica 27, 454 p. Cramer, Berlin, Stuttgart.

Lange-Bertalot, H. (1999). Neue Kombinationen von taxa aus Achnanthes Bory (sensu lato). Iconographia Diatomologica 6: 276-289.

Links & ID's

Index Nominum Algarum (INA)

Transfer INA

California Academy of Sciences (CAS)

Planothidium frequentissimum CAS

North American Diatom Ecological Database (NADED)

NADED ID: 155017

Autecology Discussion

Habits

Size Range

Motility

Attachment

Habitat

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

Planothidium frequentissimum

Distribution

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

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

Planothidium frequentissimum

Responses

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