• Category
  • Length Range
    21-46 µm
  • Width Range
    5.4-9.4 µm
  • Striae in 10 µm
  • Reported As
    Naviculadicta pseudosilicula (Lange-Bertalot and Metzeltin 1996)
    Naviculadicta pseudosilicula (Lange-Bertalot and Genkal 1999)
    Navicula pseudosilicula (Hustedt 1942)



Valves are linear, inflated in the center and sub-terminally to appear triundulate. Apices are cuneate and obtusely rounded. The axial area is very narrow. The central area is about half the width of the valve and circular. The raphe is weakly lateral with simple proximal ends curved toward the primary side of the valve. Distal raphe ends are hooked toward the secondary side. Striae are radiate in the middle and become parallel at the apices. Areolae are easily distinguished in LM and number 20-24 in 10 µm.

Further work is needed to determine the relation of B. hustedtii with Navicula lacuna Patrick & Freese 1961. Kulikovskiy et al. (2010) suggest that N. lacuna may be conspecific with N. pseudosilicula.


Boreozonacola hustedtii has been found in Lower Lost Lake, Deer Lodge County, Montana, at an elevation of 2896 meters above mean sea level. The pH of Lower Lost Lake is 6.9 and the specific conductance is 14 µS/cm. Zimmermann et al. (2010) summarize the ecology and distribution of this taxon as follows: "This common freshwater taxon is oligohalobe (indifferent), pH circumneutral and particularly frequent in arctic, alpine and boreal regions of northern Europe, Asia and North America, such as Alaska including Adak Island, as well as the Siberian Islands. In central Europe, [B. hustedtii] occurs dispersed in oligotrophic water bodies of the Alps with low electrolyte content." B. hustedtii has also been reported from Nur Bog in northern Mongolia (Kulikovskiy et al. 2010).

Lower  Lost  Lake Summitpostorg
Credit: summitpost.org
Lower Lost Lake, elev. 2896 m, Anaconda-Pintlar Wilderness, Deer Lodge County, Montana: home of Boreozonacola hustedtii.

Original Description

Valves linear, consistently inflated in the middle, minor inflated parts below the apices at least common in larger cell cycle stages; ends slightly cuneate obtusely rounded. Length 14-50 µm, breadth 4.5-10.0 µm i.e. comparatively a very wide size spectrum. Raphe characters as described for the genus. Axial area narrow, linear. Central area rather variable in size, in longer specimens larger, almost circular. Striae 17-18 in 10 µm. Areolae 20-22 in 10 µm.

  • Author
    Lange-Bert., Kulikovskiy and Witkowski 2010
  • Length Range
    14-50 µm
  • Width
    4.5-10.0 µm
  • Striae in 10µm

Original Images

Boreozonacola hustedtii orig illus
Boreozonacola hustedtii orig illus 2
Boreozonacola hustedtii orig illus 3
Boreozonacola hustedtii orig descr

Cite This Page

Bahls, L. (2011). Boreozonacola hustedtii. In Diatoms of North America. Retrieved July 21, 2018, from https://diatoms.org/species/boreozonacola_hustedtii


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