• Category
  • Length Range
    27.9-39.9 µm
  • Width Range
    6.3-7.7 µm
  • Striae in 10 µm
  • Reported As
    Pinnularia biceps var. pusilla (Camburn and Charles 2000)



Valves are linear, with straight to weakly convex sides. Apices are capitate, to subcapitate in shorter cells. The axial area is narrow and gradually widens to a rhombic central area with a broad fascia. The raphe is filiform. The proximal raphe ends are slightly expanded and bent toward the primary side of the valve. Externally, the proximal fissures are drop-shaped. Terminal fissures are shaped like a question mark. Striae are radiate in the center, becoming convergent near the apices.


P. subanglica is commonly found in lakes and often reported in acidic conditions.

Original Description

  • Author
    Krammer 2000
  • Length Range
    35-53 µm
  • Width
    7-8 µm
  • Striae in 10µm

Original Images

Pinnularia subanglica org illus
Subang Description040

Citations & Links


  • Index Nominum Algarum
  • DiatomBase
  • GenBank
  • North American Diatom Ecological Database
    NADED ID: https://diatom.ansp.org/taxaservice/ShowTaxon1.ashx?naded_id=44372

Cite This Page

Aycock, L. (2022). Pinnularia subanglica. In Diatoms of North America. Retrieved May 24, 2024, from https://diatoms.org/species/pinnularia_subanglica


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