Diatoms of North AmericaDiatoms of North America

Eucocconeis americana

Enache and Potapova 2012

Eucocconeis Americana Guide
  • Category
    Monoraphid
  • Length Range
    14.8–39.7 µm
  • Width Range
    7.8–13.4 µm
  • Striae in 10 µm
    22–32

Identification

Eucocconeis americana LM1 Eucocconeis americana LM5 Eucocconeis americana LM3 Eucocconeis americana LM4 Eucocconeis americana LM1 Eucocconeis americana LM2 Eucocconeis americana LM2
View image metadata Type
Eucocconeis americana SEM3 Eucocconeis americana SEM2 Eucocconeis americana SEM1 Eucocconeis americana SEM4

Description

Valves are elliptic-lanceolate with flat face and subrostrate apices. Raphe valve has a narrow, straight to slightly sigmoid axial area, which widens towards central area. The central area on the raphe valve is large, symmetric and transversely elliptic to rectangular. The raphe is straight to slightly sigmoid, with terminal fissures bent in opposite directions. The rapheless valve has a narrow, sigmoid axial area and a large hexagonal central area, often extended to the valve margins. Striae are radiate.

Autecology

Eucocconeis americana has been reported from Eastern North America. It was found in streams with low conductivity (12–75μS cm−1) and moderately low pH (5.0–6.3).

Original Description

Valves elliptical–lanceolate with flat face and subrostrate apices, 14.8–39.7 μm long, 7.8–13.4 μm wide. Raphe valve with narrow, straight to slightly sigmoid axial area, which widens towards central area. Central area on raphe valve large, symmetrical, transversely elliptical to rectangular. Raphe straight to slightly sigmoid with terminal endings bent in opposite directions. Rapheless valve with narrow, sigmoid axial area and large hexagonal central area often extended to the valve margins. Striae radiate, 22–32 in 10μm.

  • Author
    Enache and Potapova 2012
  • Length Range
    14.8–39.7 µm
  • Width
    7.8–13.4 µm
  • Striae in 10µm
    22–32

Original Images

Orig Illustr 2

Cite This Page

Potapova, M. (2012). Eucocconeis americana. In Diatoms of North America. Retrieved November 21, 2024, from https://diatoms.org/species/eucocconeis_americana

Responses

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