• Category
  • Length Range
    15-24.5 µm
  • Width Range
    8.3-9.0 µm
  • Striae in 10 µm



Valves are linear to linear-elliptic, with broad, round apices. The axial area is very narrow and linear. The central area is small (1.0–2.0 μm wide) slightly quadrate to slightly rectangular. The longitudinal canal is linear, and composed of one row of areolae throughout the length. The raphe is straight, with slightly expanded proximal ends. The distal raphe ends are curved. The striae are uniseriate. The striae may be nearly parallel to radiate in the valve center, becoming more radiate toward the apices. Areolae number 20–25 in 10 μm.


This taxon has been documented in lake and river surveys across North America. The images shown here are from creeks in Virginia.

Original Description

Valves of smallest stages simply elliptical, all larger ones are linear-elliptical to linear; ends broadly rounded. Length 14–30 μm, breadth 8–12 μm; ratio length- to-breadth 1.8–3. Raphe filiform, straight or both branches slightly oblique to each other; proximal ends barely expanded, distal ends shortly deflected. Axial area very narrow, about 1 μm wide, weakly expanding from the poles towards the centre. Central area more or less set off, only 1.5–2 μm wide, i.e. 1/5th or less of the valve width. Canal system about 1/4th of the valve width proximally, there arcuate around the central nodule. Striae weakly radiate or subparallel proximally, becoming gradually more strongly radiate near the ends, 15–16 in 10 μm. Areolae clearly uniseriate on almost the entire valve face but becoming opposedly biseriate close to the margins (when appropriately focussing), 20–21 in 10 μm. Canal areolae parallel to the axial area, uniseriate on either side and strongly contrasted. Flanking internal depressions are not recognisable.

SEM external view see Figs 89: 1–4. Proximal raphe ends shortly bent; distal raphe ends moderately longer curved. Cribra, virgae and vimines forming a prominent relief on the valve surface. The comparatively large cribra—each one consisting of a large number of poroids—appear uniseriate throughout at first glance, just as in LM view. Closer inspection shows them to become opposedly biseriate, often incompletely so, towards the mantle. In the middle of each paired marginal cribrum we find a circle of rather wide poroids, as is the case in D. boldtiana and several other Diploneis species. SEM internal view see Fig. 88: 33.

  • Author
    Lange-Bertalot, Fuhrmann and Cantonati 2020
  • Length Range
    14–30 µm
  • Width
    8–12 µm
  • Striae in 10µm

Original Images

Diploneis potapovae Orig Illus
Diploneis potapovae Orig Desc

Cite This Page

Jovanovska, E., Phillips, N., Polaskey, M. (2019). Diploneis potapovae. In Diatoms of North America. Retrieved November 30, 2021, from https://diatoms.org/species/diploneis-potapovae


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