• Category
  • Length Range
    16-33 µm
  • Width Range
    4.2-5.9 µm
  • Striae in 10 µm
    16-18 in the center valve, 19-20 at the ends
  • Synonyms
    Navicella pusilla (Grunow) Krammer
    Seminavis pusilla (Grunow) E.J.Cox and G.Reid



Valves are moderately dorsiventral with an arched dorsal margin. The ventral margin is flat, to slightly convex. The apices are rounded and not protracted. The axial area is narrow and widens in the valve center to form a small, lanceolate central area. The raphe is straight and weakly lateral. The external proximal ends and terminal fissures are hooked to the dorsal side. Striae are radiate in the valve center, becoming convergent at the ends. Areolae are lineolate and number 45-55 in 10 μm.


Navicymbula pusilla is found in waters of high mineral content.

Original Description

  • Basionym
    Cymbella pusilla
  • Author
    Grunow in Schmidt et al. 1875

Original Images

Npusilla  Orig Ill

Cite This Page

Potapova, M. (2011). Navicymbula pusilla. In Diatoms of North America. Retrieved April 16, 2024, from https://diatoms.org/species/navicymbula_pusilla


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