Valves are narrow and elongate becoming lanceolate in smaller valves. Apices are broadly rounded sub-rostrate to capitate. Costae are mostly primary, and number 9-15 in 10 µm. Secondary and tertiary costae are commonly present. A single rimoportula is present, oriented perpendicular to the apical axis, near one of the apices. Striae are uniseriate, not visible in LM. Apical porefields are present at each apex. Frustules are attached to the substratum, or joined in zig-zag colonies by mucilage.
Originally described from Europe, there are only a few verified records of D. ehrenbergii in the United States. We observed D. ehrenbergii growing in the epilithon in the littoral zone of Lake Michigan and Lake Superior.
Live populations are often seen in girdle view forming zigzag chains. Careful focus is required to observe the rostrate ends that distinguish this taxon from other species of Diatoma.
DIATOMA EHRENBERGII. Taf. 17. Fig. XVII. 1-3. (420/1). D. affixum, stipite minutulo; articulis validis medium versus parum contractis, a latere secundario in media parte dilatatis, prope apices capitatos contractis, isthmo pulvinato distinctissimo concatenatis; striis in 1/106'" 11.
Burge, D., Edlund, M. (2015). Diatoma ehrenbergii. In Diatoms of North America. Retrieved November 21, 2024, from https://diatoms.org/species/diatoma_ehrenbergii
The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Diatoma ehrenbergii 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.