• Category
  • Length Range
    20-85 µm
  • Width Range
    2.9-4.9 µm
  • Striae in 10 µm
  • Synonyms
    Diatoma elongatum var. tenuis (C.Agardh) Van Heurck
  • Reported As
    Diatoma tenue var. elongatum (Patrick and Reimer 1966)



Cells form zig-zag colonies. Frustules are biconcave in girdle view. In valve view, valves are linear with capitate apices. Valves at the smaller end of the size range have rostrate or subrostrate apices. Transapical ribs number 6-11 in 10 µm. Striae are uniseriate, but not visible under LM. Axial area is linear and very narrow. A rimportula is positioned within in a transapical rib or between ribs at one apex. Apical pore fields are present at both apices.

Original Description

Diatoma Tenuis, filis decumbentibus linearibus fusco-luteis, articulis post copulationem alternatim solutis. Habitat in foliis dejectis aquaque submersis, ut in rivulo Luci Foglesång prope Ludam, unde inter alias algas apportavit amic. Ph. Doct. Bruzelius.

  • Author
    C.Agardh 1812

Cite This Page

Potapova, M. (2010). Diatoma tenuis. In Diatoms of North America. Retrieved April 16, 2024, from https://diatoms.org/species/diatoma_tenuis


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