• Category
  • Length Range
    7-18 µm
  • Width Range
    5-7 µm
  • Striae in 10 µm
  • Synonyms
    Navicula aboensis (Cleve) Hust.



Valves are elliptic to elliptic-lanceolate, with rounded apices. The raphe is straight and filiform. The proximal raphe ends are straight and slightly expanded. The distal raphe ends are deflected in the same direction. Striae are uniseriate, coarsely punctate and slightly radiate. The areolae may be simple and single, or they may be arranged in pairs, or they may be divided by volae. The adaxial areolae are slightly enlarged. The central area is expanded transversely, with a variable degree of expansion across specimens. The striae surrounding the central area vary in length. The distal raphe ends deflect in the same direction.

On the exterior of the valve face, a shallow longitudinal depression is present on each side of the raphe. The mantle is unornamented, except near the distal ends where a few scattered areolae are present.

The genus Eolimna is not clearly circumscribed. With further investigation, it is likely that this taxon will be transferred out of Eolimna.


Eolimna aboensis is a rare in North America. In the United States, it has been recorded in samples primarily along the East Coast, with a few exceptions for sites in the Northern Rocky Mountains and Southern Alaska (US Geological Survey, NAWQA Program. This taxon has been reported from in lentic and lotic systems, from sites around the world (Cleve 1891, Genkal and Chekryzheva 2014, Hustedt 1952, Kulikovskiy et al. 2015).

Perley  Pond
Credit: Google Maps 2018.
Perley Pond, ME - where E. aboensis can be found.
Screen  Shot 2018 03 15 At 1 40 30  Pm
Credit: USGS BioData.
E. aboensis distribution based on USGS BioData.

Original Description

Var. aboensis Cl. - Valve elliptic, 0,012 m. m. in length and 0,0075 m. m. in breadth. Rows of puncta 12 in 0,01 m. m. shortened around the middle. Puncta 18 in 0,01 m. m. Pl. II, fig 7. Ab. 48.

  • Basionym
    Navicula torneensis var. aboensis
  • Author
    Cleve 1891
  • Length Range
    12 µm
  • Width
    7.5 µm
  • Striae in 10µm

Original Images

Navicula Torneensis Var Aboensis Orig Illus Screen Shot 2018 01 30 At 3 22 12 Pm
Navicula Torneensis Var Aboensis Orig Desc Screen Shot 2018 01 30 At 3 11 26 Pm

Cite This Page

Tyree, M., Ripple, H. (2019). Eolimna aboensis. In Diatoms of North America. Retrieved August 14, 2020, from https://diatoms.org/species/eolimna_aboensis


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