• Category
  • Length Range
    16-28 µm
  • Width Range
    4-5 µm
  • Striae in 10 µm



Valves are slender and linear-lanceolate, with subcapitate ends. The ends are more narrow than the center of the valve. The axial area is narrow and straight, widening slightly at the central area. The central area is expanded into a bow-tie shape, and may be interrupted shortened striae. Striae are radiate at the center of the valve, becoming slightly radiate to parallel at the apices. The raphe is filiform. The proximal raphe ends are slightly expanded and the distal raphe ends are unilaterally deflected.


Sellaphora disjuncta tends to occur in low abundance but relatively high frequency throughout its geographic range. This taxon has been confirmed in samples throughout the northeast, including in sites from Connecticut, Maine, New York, New Hampshire, Rhode Island, and Vermont, and has previously been reported from North Carolina, Louisiana, South Dakota, Colorado, and Idaho. It can be found in many lentic and lotic systems.

S  Disjuncta Biodata Distrib
Credit: USGS Biodata.
S. disjuncta distribution from USGS Biodata.
Credit: USGS.
USGS station 09010500 - Colorado River near Baker Gulch, Colorado, where S. disjuncta has been found.

Original Description

9. Navicula disjuncta Hust. (Fig. 451).

Schalen schmal elliptisch-lanzettlich mit breiten, kopfig abgeschnürten Enden, 23 μ lang, 4,5 μ breit. Zentralarea quer-recht-eckig. Transapikalstreifen radial, 26 in 10 μ, die mittleren gleichmäßig verkürzt und etwas weiter stehend.

Sehr selten im Gr. Madebrokensee bei Plön in Holstein!

  • Basionym
    Navicula disjuncta
  • Author
    Hust. 1930
  • Length Range
    23 µm
  • Width
    4.5 µm
  • Striae in 10µm

Original Images

Navicula disjuncta orig illus
Navicula disjuncta orig desc

Cite This Page

Polaskey, M., Ripple, H. (2018). Sellaphora disjuncta. In Diatoms of North America. Retrieved September 22, 2021, from https://diatoms.org/species/sellaphora_disjuncta


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