• Category
  • Length Range
    18.4-19.4 µm
  • Width Range
    5.0-5.6 µm
  • Striae in 10 µm



Valves linear with central parallel margins and distinctly capitate apices. Striae are radiate, becoming nearly parallel at the apices. The central area is bowtie-shaped, with irregularly placed shortened striae. The axial area is narrow and linear. The raphe is filiform with unilaterally deflected distal ends. Areolae are coarse and visible in LM, numbering 20-24 in 10 µm.

Note that Navicula kotschyi lacks the features of the genus Navicula sensu stricto, and is due for inclusion in another (to be described?) genus.

The species N. savannahiana and N. texana may be conspecific with N. kotschyi, as suggested by Potapova (2013). These three taxa require further comparision to determine if they are indeed distinct species.


Nakotschyi  Biodata Map
Credit: USGS BioData
Distribution of Navicula kotschyi in rivers of the continental U.S. based on the National Water Quality Assessment program. Retrieved 02 May 2016.

Original Description

Navicula Kotschyi nov. spec.

Navicula parvula (hine inde subserians) a latere secundario oblonga apicibus productis capitatis, nodulo centrali magno quadrangulari saepe cruciformi dilatato, striis transversalibus punctatis radiantibus, centralibus distinctioribus 36-40 in 0.001'' terminalibus tenuioribus ad 50 in 0.001''. Longit. 0.0005-0.0008'', latid. 0.0002-0.00025''.

Habitat in aqua calida termarum Budensium, ubi legerunt ell. de Heufler ct Kotschy auctumno anni 1850 (inter Oscillariam maximam Kg.). Tab. nostr. II, Fig. 12 (400/1).

Aehnlich der vorigen Art, aber schmäler und noch feiner gestreift. Der Mittelknoten ist bei vielen Exemplaren mehr oder weniger erweitert, so dass ich lange genegt war, sie als Stauroneis aufzuführen. In den meisten Fällen ist der Mittelknoten jedoch quadratisch, so dass ich sie endlich zu Navicula gestellt habe, wo sie entschieden in dieser Gruppe ihre nächsten Verwandten hat. Man könnte sie für eine Jugendform der Navicula dicephala Kg. halten, wogegen jedoch ihr massenhaftes constantes Vorkommen spricht, in dem sich kein Exemplar der N. dicephala vorfand.

  • Author
    Grunow 1860

Original Images

N Kotschyi Origdesc

EMAP Assessment

EMAP Distribution

Navicula Kotschyi  Grunow 3
Map 3

Response Plots

Navicula Kotschyi  Grunow

Cite This Page

Tyree, M, and Bishop, I. (2015). Navicula kotschyi. In Diatoms of North America. Retrieved August 18, 2018, from https://diatoms.org/species/navicula_kotschyi


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