• Category
  • Length Range
    12.0-45.8 µm
  • Width Range
    5.4-12.5 µm
  • Striae in 10 µm
    9-11 at the valve center, up to 13 at the apices



Valves are dorsiventral and rhombic-lanceolate with rounded apices. The dorsal margin is moderately arched. The ventral margin is somewhat less arched and slightly tumid in the largest specimens. The axial area is a bit wider than the raphe and lies just ventral of the valve mid line. The central area is a somewhat wider continuation of the axial area and, in some specimens, is defined by one or two shorter striae on the dorsal side. The raphe is distinctly lateral and bowed, narrowing toward the proximal and terminal ends. Proximal raphe ends are deflected ventrally and terminate in slightly inflated pores. Distal raphe fissures are deflected dorsally at about a 45 degree angle. Striae are nearly parallel at the valve center, becoming strongly radiate at the apices. The areolae are very distinct in LM and number 18-22 in 10 µm. A stigma is lacking.


Most specimens of C. neoleptoceros that are shown on this web page were collected from Lower Wolverine Lake in northwest Montana (photo below). At the time of collection, pH of this lake measured 9.01 and electrical conductance measured 100 µS/cm. The remaining specimen was collected from a kettle lake in North Dakota. This lake had a pH of 9.00 and specific conductance of 1693 µS/cm. Krammer (2002) reports this widespread species as epiphytic and epilithic in brooks and lakes of the Alps and abundant in many calcium-saturated rivers and lakes of the Karst region of the Balkans. It has been reported from oligotrophic to slightly mesotrophic waters with average electrolyte content.

Lower  Wolverine  Lake 2
Credit: Loren Bahls
Lower Wolverine Lake, Lincoln County, Montana: home of Cymbella neoleptoceros

Original Description

  • Author
    Krammer 2002
  • Length Range
    21-51 µm
  • Width
    8-12 µm
  • Striae in 10µm
    8.5-11 at the valve center, 12 near the apices

Original Images

Cymbella neoleptoceros orig desc
Cymbella neoleptoceros orig illus
Cymbella neoleptoceros orig descr2

Citations & Links


  • Index Nominum Algarum
  • North American Diatom Ecological Database
    NADED ID: 23201

Cite This Page

Bahls, L. (2016). Cymbella neoleptoceros. In Diatoms of North America. Retrieved May 24, 2024, from https://diatoms.org/species/cymbella_neoleptoceros


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