• Category
  • Length Range
    20–22 µm
  • Width Range
    11-13 µm
  • Striae in 10 µm



Valves are elliptic to linear-elliptic, with rounded apices. The axial area is narrow and linear. The axial area expands in the middle valve, forming an elliptic central area, 2.8–3.0 µm wide. The longitudinal canal is lanceolate and composed of two rows of areolae throughout. The raphe is straight, with slightly expanded central ends. The striae are radiate. Striae are composed of two rows of round areolae. The arrangement of areolae is variable, from opposite to altering in pattern. Areolae number 20 in 10 μm.


This taxon was documented from lake sediments of Crosby Pond, Maine and Lower Spectacle Lake, Massachusetts in an EPA survey of Northeast Lakes.

Original Description

Valves elliptical or more often linear–elliptical with bluntly rounded apices. Length 15–30 μm, breadth 9–14.5 μm. Length–to–breadth ratio 1.7–2.1. Raphe filiform, straight with slightly marked central ends and inconspicuous distal ends. Narrow depressions flanking the internal raphe slit. Axial area as a whole is very narrow, linear. Central area is very small, hardly expanded circularly or elliptically, without any recognizable H–shaped appendices (horns). The internal longitudinal canals on either side are narrow, marked externally by a row of indistinct puncta. Transapical striae are radiate throughout, more strongly near the ends, appearing comparatively coarse, 11–13 in 10 μm, being composed of two rows of opposed to alternating areolae, 22–26 in 10 μm. SEM external and internal view, see Figs 130–133. External view (Fig. 133) exhibits a slightly curved raphe slit with shortly bent central ends depressed into the valve surface and a small, gently deflected distal groove. A differentiated terminal fissure is lacking. Cribra above underlying canals appear somewhat irregularly distributed, uni– to biseriate; cribra of adjacent striae appear more closely condensed, biseriate to finally confluent onto the barely differentiated mantles. Internal view with uncorroded closing membranes see Fig. 132, after corrosion see Figs. 130–131. The relief of canals, central nodule and virgae is rather high. The raphe slit lying in a narrow, particular raphe rib is separated from the canals by depressions which appear as dark lines in LM view. In open alveoli the areolae are arranged opposed biseriate closer to the canals, becoming gradually alternating and finally even triseriate at valve margins.

  • Author
    Lange-Bert. and Fuhrmann 2016
  • Length Range
    15-30 µm
  • Width
    9-14.5 µm
  • Striae in 10µm

Original Images

Diploneis Puellafallax Orig Illus 2
Diploneis Puellafallax Orig Illus
Diploneis Puellafallax Orig Desc

Cite This Page

Jovanovska, E., Phillips, N., Polaskey, M. (2019). Diploneis puellafallax. In Diatoms of North America. Retrieved May 30, 2024, from https://diatoms.org/species/diploneis-puellafallax


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