• Category
  • Length Range
    29-50 µm
  • Width Range
    10-13 µm
  • Striae in 10 µm
    7-10 in the center valve, 10-16 at the ends

Identification

Description

Valves are highly arched. The dorsal margin is undulate . The number of dorsal undulations and their depth is variable within the species , but generally ranges from 5 to 8. The ventral margin is straight or slightly concave. The apices are protracted and terminate bluntly, with a slight ventral curvature. Two types of striae are present; full striae are widely spaced and extend from margin to margin, irregular striae are very short and restricted to the dorsal margin near the center valve. Shortened striae are absent from the valve apices. Valves possess one apical rimoportula. Internally, the openings of the areolae are aligned in the bottom of a narrow groove in the inner valve surface (SEM).

Autecology

Eunotia bilii is found epiphytic on bryophytes, in first through fourth order streams and wet walls, especially throughout the Great Smoky Mountains National Park.

Gsm 6 28 05  L6 Bf 0311
Credit: Linda Novitski
Eunotia bilii has been collected from rivers such as this in the Great Smoky Mountains National Park: Hazel Creek.
Gsm 8 10 05 8  F 0103 1
Credit: Paula C. Furey
Eunotia bilii has been collected from rivers such as this in the Great Smoky Mountains National Park: Otter Creek.
Gsm 7 15 05 3 Seep 1
Credit: Paula C. Furey
Eunotia bilii has been collected from wet walls such as this. Chimney Tops Trail, Great Smoky Mountains National Park.

Original Description

Valves highly arched, dorsal margin undulate, with number and depth of undulations variable. Ventral margin straight or slightly concave. Valve length: 32-46 μm, breadth 10-13 μm. Ends protracted but terminating bluntly, with a slight ventral curvature at the ends. Full striae widely spaced, with irregular shortened striae at the dorsal margin near mid-valve. Shortened striae not present at valve ends. Number of striae 9-10 μm.

  • Author
    R.L.Lowe and Kociolek 1984
  • Length Range
    32-46 µm
  • Width
    10-13 µm
  • Striae in 10µm
    9-10

Original Images

Eunotia bilii orig illus
Eunotia Bilii  Text Scan

Cite This Page

Furey, P. (2011). Eunotia bilii. In Diatoms of North America. Retrieved July 22, 2018, from https://diatoms.org/species/eunotia_bilii

Responses

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