• Category
  • Length Range
    50.6-116.3 µm
  • Width Range
    8-10.7 µm
  • Striae in 10 µm
  • Synonyms
    Nitzschia brunoi Lange-Bert.
  • Reported As
    Nitzschia angustata (Krammer and Lange-Bertalot 1988 pg 48, Pl 36, Fig 2-3)



Valves are linear. Apices are wedge-shaped with narrowly rounded ends. Like other species in the genus Tryblionella, the valve face has a longitudinal undulation. The raphe is eccentric, and positioned within a keel. The keel is along the valve margin from pole to pole. Transapical striae are parallel throughout the entire valve. Striae are distinctly punctate, formed by coarse areolae (18-21 in 10 µm). Fibulae appear as dark lines. Individual fibula are difficult to distinguish with light microscopy.


Tryblionella brunoi was found growing in association with the flowering aquatic plant, Ceratophyllum, in West Lake Okoboji, Dickinson County, Iowa. A collection in the Iowa Lakeside Lab Reimer Herbarium contained specimens collected on Typha and Cladophora from Lower Gar Lake, Dickinson County, Iowa. Specimens from the two samples are represented in the size series below.

In Europe, T. brunoi is abundant in carbonate-rich waters (Lange-Beralot and Metzeltin 1996). The species is commonly found in mesotrophic or oligotrophic waters, though it has been found in low numbers in eutrophic waters, too (Hofmann et al. 2011). Tryblionella brunoi was described in a sample from Mittersee, a lake in the North Tyrol limestone Alps of Austria (Lange-Beralot and Metzeltin 1996).

Tryblionella brunoi Size Series
Specimens from West Lake Okoboji and Lower Gar Lake, Iowa.

Original Description

Valvae lineares apicibus asymmetricae apparentes obtuse cuneatae et obtusissime vel plerumque late rotundatae. Longitudo 45-180 μm, latitudo 9-13 μm. Carina raphis sine fibulus aspectabilibus quia fibulae in costis transapicalibes continent. Striae transabicales grossae, 12-13 μm. Series striatarum et punctorum non interruptae una ruga apicalis. Structurae submicroscopicae se praestant in figuris tabularum 101: 12-15 et 102: 1 (in comparatione cum Nitzschia angustata fig. 102:2).

  • Basionym
    Nitzschia brunoi
  • Author
    Lange-Bert. and Metzeltin 1996
  • Length Range
    45-180 µm
  • Width
    9-13 µm
  • Striae in 10µm

Original Images

Tryblionella Brunoi Orig Illus
Tryblionella Brunoi Orig Desc

Cite This Page

Powers, M. (2018). Tryblionella brunoi. In Diatoms of North America. Retrieved July 24, 2024, from https://diatoms.org/species/tryblionella-brunoi


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