Diatoms of North AmericaDiatoms of North America

Eunotia cataractarum

Furey, Lowe and Johansen 2011

Eunotia Cataractarum Guide
  • Category
    Eunotioid
  • Length Range
    11-21 µm
  • Width Range
    3.1-3.9 µm
  • Striae in 10 µm
    15-20 in the center valve, 16-19 at the ends, puncta 44-50

Identification

Eunotia cataractarum LM5 Eunotia cataractarum LM6 Eunotia cataractarum LM1 Eunotia cataractarum LM4 Eunotia cataractarum LM3 Eunotia cataractarum LM2 Eunotia cataractarum LM7
View image metadata
Eunotia cataractarum SEM4 Eunotia cataractarum SEM3 Eunotia cataractarum SEM2 Eunotia cataractarum SEM1

Description

Valves are concave on the ventral margin, sometimes with scarcely visible swellings on the ventral margin, marking the position of the proximal raphe ends. Valves have a slightly convex, flattened dorsal margin. The apices are set off dorsally by a fairly steep sloping shoulder. Apices are capitate and rounded. Helictoglossae are not visible in the LM. One apical rimoportula at the center of the apex, with a distinct external pore (visible in SEM). Striae are parallel to slightly radiate.

Autecology

Eunotia cataractarum is commonly found in the epilithon or epiphytic on bryophytes at waterfalls, and occasionally in streams in the Great Smoky Mountains National Park.

Original Description

Valves concave on the ventral margin, sometimes with scarcely visible swellings marking the position of the proximal raphe ends. Slightly convex flattened dorsal margin, with apices set off dorsally by a fairly steep sloping shoulder. Apices capitate, rounded. Helictoglossae not visible in the light microscope. Rimoportula at one end of valve, at the center of the apex, with a distinct external pore. Striae parallel to slightly radiate, 15 – 20 in 10 μm in the valve center, 16 – 19 in 10 μm at the apices. Puncta 44 – 50 in 10 μm.

  • Author
    Furey, Lowe and Johansen 2011
  • Length Range
    11-21 µm
  • Width
    3.1-3.9 µm
  • Striae in 10µm
    15-20 in the center valve, 16-19 at the ends, puncta 44-50

Original Images

Eunotia cataractarum orig illus
Eunotia cataractarum orig illus 2
Eunotia Cataractarum Textscan2

Cite This Page

Furey, P. (2011). Eunotia cataractarum. In Diatoms of North America. Retrieved April 18, 2024, from https://diatoms.org/species/eunotia_cataractarum

Responses

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