• Category
  • Length Range
    30.5-36.4 µm
  • Width Range
    9.9-13 µm
  • Striae in 10 µm
    23-25 in the center valve, 25-29 in the ends
  • Reported As
    Navicula accomoda (Krammer and Lange-Bertalot 1986, pg. 128, figs 45: 18-19)



Valves lanceolate-elliptical with rostrate apices and rounded ends. Striae are parallel at the valve center, becoming weakly radiate along most of the valve length, parallel then weakly convergent near the apices. Stria density increases towards the valve apices. Areolae are fine and not visible in LM. The axial area is narrow. The central area is slightly expanded. The raphe is filiform, with inflated proximal ends. The distal raphe ends sharply deflected to the same direction.


We verified occurrences of C. accomodiformis in the Iowa River, Iowa and Buffalo Creek, Texas, within watersheds heavily dominated by agriculture.

Outside of the U.S, C. accomodiformis is reported to occur in central Europe and the subtropics in association with mesosaprobic and polysaprobic taxa (Lange-Bertalot 1993).

Usgs  Biodata  C Accomodoformis Map
Credit: USGS BioData
Distribution of Craticula accomodiformis in rivers of the continental U.S. based on the National Water Quality Assessment program. Retrieved 03 June 2015.

Original Description

Valvae ad instar et quoad strias et areas et raphem generaliter Craticula accomoda valde similes, sed tamen semper maiores, longitudo (24?)28-35(37)µm, latitudo 8-11.5 µm; striae 20-28/10 µm, nodulum centralem versus distantiores positae, 17-25/10 µm (sicut C. accomoda). A C. accomoda differt habitatione conditionibus aquarum non pollutis.

  • Author
    Lange-Bert. 1993
  • Length Range
    28-35 µm
  • Width
    8-11.5 µm
  • Striae in 10µm

Original Images

Craticula accomodiformis orig illus
Craticula accomodiformis orig descr

Cite This Page

Bishop, I., Burge, D. (2015). Craticula accomodiformis. In Diatoms of North America. Retrieved June 21, 2024, from https://diatoms.org/species/craticula_accomodiformis


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