Diatoms of North AmericaDiatoms of North America

Navicula weberi

Bahls 2012

Navicula Weberi Guide
  • Category
    Symmetric Biraphid
  • Length Range
    29-58 µm
  • Width Range
    7.3-10.3 µm
  • Striae in 10 µm
    9-10

Identification

Navicula weberi LM4 Navicula weberi LM3 Navicula weberi LM2 Navicula weberi LM1 Navicula weberi LM7 Navicula weberi LM6 Navicula weberi LM5
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Description

Valves are elliptic-lanceolate to broadly lanceolate, with obtusely rounded apices. The raphe is weakly lateral. Proximal raphe ends are deflected to the secondary side. Distal raphe fissures are hooked to the secondary side. The axial area is very narrow. The central area is moderately large, rounded and asymmetric. Striae are radiate, becoming convergent at the apices. Areolae are coarse, easily distinguished in LM and number 24 in 10 μm.

Autecology

Navicula weberi has been collected from 20 lakes and streams in the Northern Rocky Mountains of western Montana, where it is present in low numbers. Here it prefers alkaline waters (pH range = 7.4-9.1) with low to moderate levels of electrolytes (specific conductance range = 49-256 μS/cm).

Our Lake 1
Credit: Loren Bahls
Our Lake in the Bob Marshall Wilderness near Choteau, Montana. Our Lake is home to Navicula weberi.

Original Description

Valves elliptic-lanceolate to broadly lanceolate with obtusely rounded ends, 29 – 57 μm long, 7.3 –10.3 μm wide. Raphe weakly lateral, proximal endings deflected to the secondary side, distal raphe fissures hooked to the secondary side. Axial area very narrow, central area moderately large, rounded and asymmetric. Striae radiate, becoming convergent at the ends, 9 –10 in 10 μm, lineolae coarse, 24 in 10 μm, easily distinguished in LM. For measurements, n = 23.

  • Author
    Bahls 2012
  • Length Range
    29-57 µm
  • Width
    7.3-10.3 µm
  • Striae in 10µm
    9-10

Original Images

Nweberi Origimag
Nweberi Origdesc

Cite This Page

Bahls, L. (2012). Navicula weberi. In Diatoms of North America. Retrieved April 19, 2024, from https://diatoms.org/species/navicula_weberi

Responses

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