• Category
  • Length Range
    40-50 µm
  • Width Range
    16-17 µm
  • Striae in 10 µm
  • Synonyms
    Mastogloia pseudotuscula (Hust.) Loseva 1982



Valves are lanceolate with protracted apices. The axial area is relatively straight and expanded in the center to form an unequal, irregular rectangular central area. The raphe is lateral and reverse-lateral. The external proximal raphe ends are dilated. Striae are radiate, except at the apices where they become parallel. Striae are composed of small, nearly square to dash-like areolae.

This species has only been confirmed in the upper midwest of the U.S.


Original Description

Navicula pseudotuscula nov. spec. (Syn.: Navicula arata Hust., Bot. Arch. 38, S. 194, F. 21, 22, non N. arata Grun.!). Schalen linear-elliptisch mit mehr oder weniger stark geschnäbelten bis schwach kopfig abgeschnürten Enden, 35-70 µ lang, 12-17 µ breit. Raphenäste gerade, nur mit einer kaum merklichen Ausbuchtung der äußeren Raphenrinne, Polspalten klein, nach derselben Seite abgebogen. Axialarea sehr eng, linear, Zentralarea eine schmale, kurze, unregelmäßig begrenzte Querbinde. Transapikalstreifen im allgemeinen leicht radial, an den Polen senkrecht zur Mittellinie, etwa 14 in 10 µ, zart, aber deutlich punktiert, Punkte in der Randzone dichter stehend, gegen die Mittellinie etwas aufgelockert, hier etwa 10-12 in 10µ.

  • Basionym
    Navicula pseudotuscula
  • Author
    Hust. 1943

Original Images

Navicula pseudotuscula orig illus
Aneumastus pseudotuscula orig descr

Cite This Page

Kociolek, P. (2011). Aneumastus pseudotusculus. In Diatoms of North America. Retrieved June 23, 2024, from https://diatoms.org/species/aneumastus_pseudotusculus


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