Identification

Description

Valves are elliptic, with convex margins and rounded apices. The axial area is narrow-lanceolate, expanding slightly from the apices to the central area. The central area is large and round. Longitudinal canals are present on both sides of the axial and central areas. Longitudinal canals are widest near the central area and narrow towards the valve apices. The raphe is straight with expanded proximal raphe ends. Terminal raphe fissures deflect unilaterally, terminating short of the valve margin. Striae are radiate mid-valve, becoming strongly radiate towards the apices. Striae composed of complex, round to rectangular areolae. Striae are uniseriate. Areolae number 11-14 in 10 µm. Usually one row of areolae is positioned along the longitudinal canal, but in some specimens, two rows may occur.

Autecology

Diploneis elliptica was found in a benthic sample in Cold Creek, San Bernardino County, California. Diploneis elliptica was also found in mud surface and moss squeeze in Excelsior Fen, Dickinson County, Iowa. The genus Diploneis is typically associated with epipelon and can be found in freshwater, brackish, and marine environments (Cleve 1894).

Other distributional and ecological records include Iceland, Sweden, Finland, Germany, England, New Zealand, North America, and Ecuador (Cleve 1894). In a collection from Lake Hövsgöl, an ancient and large freshwater lake in north-central Mongolia, 25 Diploneis taxa were identified (Jovanovska et al. 2015). Diploneis elliptica was found on sand, epipelon, sediments, marl habitats, and epiphytic on Chara, a green algae (Jovanovska et al. 2015).

Diploneis Elliptica1
Credit: USGS BioData
Distribution of Diploneis elliptica in rivers of the continental U.S. based on the National Water Quality Assessment program. Retrieved 16 June 2015.
Diploneis Elliptica2
Credit: USGS BioData
Distribution of Diploneis elliptica in rivers of Alaska based on the National Water Quality Assessment program. Retrieved 16 June 2015.

Original Description

  • Basionym
    Navicula elliptica
  • Author
    Kütz. 1844
  • Striae in 10µm
    12-13

Original Images

Diploneia elliptica orig illus
D Ellipticia Orig Des

EMAP Assessment

EMAP Distribution

Diploneis Elliptica   Kùtzing   Cleve 10
Map 10

Response Plots

Diploneis Elliptica

Cite This Page

Kamae, B. (2015). Diploneis elliptica. In Diatoms of North America. Retrieved July 21, 2018, from https://diatoms.org/species/diploneis_elliptica

Responses

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