• Category
  • Length Range
    6.0-12.1 µm
  • Width Range
    2.4-2.6 µm
  • Striae in 10 µm
  • Synonyms
    Diadesmis contenta (Grunow) Mann



Cells are linear, with slightly concave or slightly convex margins. The raphe is straight and simple. A central fascia is present, extending from the central nodule to the valve margins. Striae are difficult to resolve using light microscopy. The axial area is broad and linear. In SEM, the proximal raphe ends are bilaterally expanded in a T-shaped depression. The distal raphe ends have a longer bilaterally expanded T-shaped depression. Cells often grow attached to one another in short chains.


Humidophila contenta is one of the few cosmopolitan species of this genus. It has been reported worldwide in soils and subaerial habitats.

Original Description

  • Basionym
    Navicula contenta
  • Author
    Grunow in Van Heurck 1885
  • Length Range
    7 µm
  • Width
    2 µm
  • Striae in 10µm

Original Images

Navicula contenta orig descr

Cite This Page

Lowe, R. (2015). Humidophila contenta. In Diatoms of North America. Retrieved April 21, 2024, from https://diatoms.org/species/humidophila_contenta


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