• Category
  • Length Range
    10–40 µm
  • Width Range
    2.5-6.0 µm
  • Striae in 10 µm
  • Synonyms
    Diatoma tenue var. moniliforme Kütz.



Cells form zig-zag colonies. Frustules are rectangular in girdle view, valves are elliptical to lanceolate with rounded to subrostrate apices, valves are 10-40 µm in length and 2.5-6.0 µm in width. Transapical ribs number 6-11 in 10 µm. Striae are uniseriate and composed of small poroid areolae, 50-60 in 10 µm. Axial area is linear, very narrow. One rimportula is positioned within in a transapical rib at one, or both, valve apices. Apical pore fields are present at both apices.


Fresh and brackishwater. Forms zig-zag colonies attached to substrates by a mucilage pad.

Original Description

Frustulis quadraticis, longam seriam formatibus.

  • Author
    Kütz. 1831

Original Images

Diatoma moniliforme orig illus
Damonil  Orig Descr

Cite This Page

Potapova, M. (2009). Diatoma moniliformis. In Diatoms of North America. Retrieved July 15, 2024, from https://diatoms.org/species/diatoma_moniliformis


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