Diatoms of North AmericaDiatoms of North America

Navicula pseudotenelloides

Krasske 1938

Navicula pseudotenelloides guide
  • Category
    Symmetric Biraphid
  • Length Range
    18-25 µm
  • Width Range
    2.7-3.3 µm
  • Striae in 10 µm
    13-14

Identification

Navicula pseudotenelloides LM1 Navicula pseudotenelloides LM5 Navicula pseudotenelloides LM4 Navicula pseudotenelloides LM3 Navicula pseudotenelloides LM2 Navicula pseudotenelloides LM7 Navicula pseudotenelloides LM6
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Navicula Pseudotenelloides ANSP PF43 015 SEM

Description

Valves are linear, with rounded ends. The raphe is straight and filiform. The axial area is linear and narrow. The central area is small, formed by one or two shortened striae on each valve side. Striae are radiate in the central valve and weakly convergent at the apices. Areolae are indistinguishable under LM.

Note that specimens shown on this page are from Alaska. They are more narrow (2.9-3.2 µm) than specimens of the Spitsbergen type population (3.0-4.5 µm) (Krasske 1938). Similarly, Lange-Bertalot (2001) published images of wider specimens (3.2-3.6 µm).

Autecology

Lange-Bertalot (2001) noted that this taxon is only known from arctic and subarctic regions. He illustrated specimens from Spitsbergen and Siberia. Specimens illustrated here are from two freshwater locations in the vicinity of Point Barrow, Alaska, and originated from Leonard Freese's 1959 collection (Patrick and Freese 1961). 

Original Description

  • Author
    Krasske 1938
  • Length Range
    18-21 µm
  • Width
    3.5-4 µm
  • Striae in 10µm
    14

Original Images

Navicula Pseudotenelloids Orig Descr

Cite This Page

Potapova, M., Leppik, S. (2024). Navicula pseudotenelloides. In Diatoms of North America. Retrieved March 19, 2025, from https://diatoms.org/species/62299/navicula-pseudotenelloides

Responses

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