Navicula pseudolanceolata | Species - Diatoms of North America

Category

Symmetric Biraphid
Length Range

41-59 µm
Width Range

9.0-11.1 µm
Striae in 10 µm

9-11

Contributor

Loren Bahls - Dec 2011
Reviewer

Marina Potapova - Nov 2011

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Identification

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Description

Valves are lanceolate, with acutely pointed apices in smaller specimens and weakly protracted, narrowly rounded apices in larger specimens. The axial area is narrow, widening into a small rhombic central area. The raphe is weakly lateral and essentially straight, with relatively distant and only slightly expanded proximal ends. Striae are irregularly shortened and more widely spaced about the central area, strongly radiate and mostly straight, becoming parallel, but not convergent at the valve apices. Lineolae are coarse and number 24 in 10 µm.

Autecology

There are 82 records of Navicula pseudolanceolata in the Montana Diatom Collection, from lakes and streams in mountain regions of the Northwest United States. The species is rarely found in abundance. Specimens pictured here are from Lower Branham Lake in the Tobacco Root Mountains of southwest Montana. At the time of sampling this lake had a pH of 8.74 and specific conductance of 64 µS/cm. Lange-Bertalot (2001) reports N. pseudolanceolata from low conductivity or weakly humic acid and oligotrophic lakes in Europe.

Size Range, µm3

1001-10000
Motility

Moderately motile
Attachment

Unattached
Habitat

Benthic
Colony

Solitary
BCG

BCG 2
Waterbody

Inland
Distribution

California coastal rivers 2017
Learn more about this

Credit: Loren Bahls

Lower Branham Lake, Madison County, Montana: home of Navicula pseudolanceolata.

Original Description

Valves lanceolate to rhombic-lanceolate, ends gradually narrowed, wedge-shaped, length 30-50 microns, breadth 7-9.5 microns. Raphe weakly lateral, axial area narrow, central area small to moderately larger, slightly rhombic to transversely widened. Striae strongly radiate throughout or parallel at the ends, 9.5-11/10 microns; lineolae appear coarse, c. 24/10 microns.

Author

Lange-Bert. 1980
Length Range

30-50 µm
Width

7-9.5 µm
Striae in 10µm

9.5-11

Original Images

Citations & Links

Citations

Cite This Page

Bahls, L. (2011). Navicula pseudolanceolata. In Diatoms of North America. Retrieved December 21, 2024, from https://diatoms.org/species/47673/navicula_pseudolanceolata

Responses

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