• Category
  • Length Range
    35-40 µm
  • Width Range
    9.1-11.4 µm
  • Striae in 10 µm
    10-16 at center valve, 15-19 at the ends
  • Reported As
    Cymbella naviculiformis (Patrick and Reimer 1975, plate 4, fig. 9)
    Cymbella naviculiformis (Krammer and Lange-Bertalot 1986, fig. 145: 6-11)



Valves are elliptic-lanceolate and moderately dorsiventral, with a strongly arched dorsal margin and a slightly convex to nearly flat ventral margin. Apices are rostrate to subcapitate. The axial area is narrowly lanceolate and expands gradually towards a large rounded central area. The raphe is lateral and becomes filiform near the proximal ends, which are deflected slightly towards the ventral margin. Proximal raphe ends are not expanded and tipped with short hooks. Distal raphe ends are deflected dorsally. Striae are slightly radiate throughout and somewhat more closely spaced on the ventral side. Areolae number about 35 in 10 µm.


Cymbopleura naviculiformis is widely distributed in small lakes and streams in mountain regions of the Northwest United States. Here it prefers well oxygenated, circumneutral and slightly alkaline waters with low concentrations of dissolved solids (see table below). In contrast, C. amphicephala prefers waters with higher pH, alkalinity, and dissolved solids. Patrick & Reimer (1975) report Cymbella naviculiformis as widely distributed throughout the United States.

Cymbonaviculiformis Chem
Credit: Montana Diatom Database
Abundance-weighted means of selected water quality variables measured concurrently with the collection of samples containing Cymbopleura naviculiformis.
Paradise  Spring  Brook  Sinopah
Credit: Loren Bahls
Paradise Spring Brook, Glacier National Park, Montana: home of Cymbopleura naviculiformis.

Original Description

  • Basionym
    Cymbella naviculiformis
  • Author
    Auersw. ex Heib. 1863

Original Images

Cymbella naviculiformis orig desc
Cymbella naviculiformis orig illus
Cymbella naviculiformis orig descr

Cite This Page

Bahls, L. (2012). Cymbopleura naviculiformis. In Diatoms of North America. Retrieved July 15, 2024, from https://diatoms.org/species/cymbopleura_naviculiformis


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