• Category
  • Length Range
    17.8–26.5 µm
  • Width Range
    4.2–5.4 µm
  • Striae in 10 µm



Valves are lanceolate, with wedge-shaped obtusely rounded apices. The axial area is narrow and linear. The central area is small, symmetric, and rhombic to rounded. The raphe is lateral, with hook-shaped terminal raphe fissures. The proximal part of the external raphe slit is undulate. The proximal raphe pores are expanded and bent toward the secondary valve side. Internally, the proximal raphe ends are connected by a shallow groove across the central nodule. Each proximal raphe end has a short extension, sharply deflected toward the secondary valve side. Striae are strongly radiate and bent in the valve center. Striae are parallel at the ends. Long and short striae alternate in the central part of the valve.


The rivers where this taxon was found had circumneutral water (pH 6–8.7, median 7.7) of variable mineral content (conductivity 44–1205 µS cm–1), but most sites had rather soft water (median conductivity 123 µS cm–1). These rivers were either nutrient-poor or had slightly elevated nutrient concentrations. Total nitrogen varied from 0.1 to 1.12 mg L–1, with a median value of 0.29 mg L–1, while total phosphorus measured 0.003–0.3 mg L–1, with a median value of 0.02 mg L–1. Navicula eileeniae reached its highest relative abundance (23.4%) in a sediment sample from Mudlick Creek, a small Virginia stream with water pH of 7.9 and conductivity of 200 µS cm–1.

Original Description

  • Basionym
    Navicula eileeniae
  • Author
    Potapova and Ciugulea 2019
  • Length Range
    17.8-26.5 µm
  • Width
    4.2-5.4 µm
  • Striae in 10µm

Original Images

Navicula Eileeniae Orig Ill
Navicula Eileeniae Orig Descr

Cite This Page

Potapova, M., Ciugulea, I. (2020). Navicula eileeniae. In Diatoms of North America. Retrieved July 24, 2024, from https://diatoms.org/species/navicula-eileeniae


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