Platessa conspicua | Species - Diatoms of North America

Category

Monoraphid
Length Range

7.0-17.5 µm
Width Range

3.6-5.4 µm
Striae in 10 µm

12-16

Synonyms

Planothidium conspicuum (Mayer) Aboal in Aboal, Alvarez-Cobelas, Cambra and Ector
Reported As

Achnanthes pinnata (Patrick and Reimer 1966)

Contributor

Marina Potapova - Dec 2010
Reviewer

Sam Rushforth - Jul 2011

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Identification

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Description

Valves are linear-elliptic. The raphe valve has a narrow axial area and transversely rectangular central area that reaches both valve margins. The rapheless valve has a lanceolate axial area and no distinct central area, though the two middle striae may be slightly more distant from each other than less central striae. The raphe is straight, with slightly expanded terminal and central ends, without terminal fissures. Internally (SEM), the central raphe ends curve toward opposite sides. Striae are almost parallel in the valve center, but become strongly radiate approaching the poles of both valves, biseriate, 12-16 in 10 µm. A single row of areolae exists on the valve mantle, with each areola opposed to a biseriate stria. The external and internal openings of the areolae are circular or somewhat angular, isodiametric.

Autecology

Size Range, µm3

11-100 101-1000
Motility

Slightly motile
Attachment

Unattached
Habitat

Benthic
Colony

Solitary
BCG

BCG 3
Waterbody

Inland
Distribution

Western rivers 2004 California coastal rivers 2017 Northeast lake sediments Great Lakes inventory
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Original Description

A. valvis prorsus ovalibus finibus rotundatis, 0,01—0,012 mm longis, 0,0055 mm latis; striis paene parallelis, ad fines subradiantibus, duobus mediis utriusque valvae perspicue distinctis, ab interiore parte ad exteriorem subappropin-quantibus, interdum una stria tenuissima in valva inferiore inter strias medias magis distantes intercalata, striis validis, 13—14 intra 0,01 mm

Basionym

Achnanthes conspicua
Author

A.Mayer 1919
Length Range

10-12 µm
Width

5.5 µm
Striae in 10µm

13-14

Original Images

Citations & Links

Citations

Cite This Page

Potapova, M. (2010). Platessa conspicua. In Diatoms of North America. Retrieved December 16, 2024, from https://diatoms.org/species/45105/platessa_conspicua

Responses

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