• Category
  • Length Range
    32-60 µm
  • Width Range
    8.1-10.4 µm
  • Striae in 10 µm
    10-11

Identification

Description

Valves are lanceolate with obtusely rounded ends that are short and cuneate in small specimens to long and protracted in larger specimens. The axial is area narrow, widening into a variable rhombic to transversely elliptic central area. The raphe is lateral. Proximal raphe ends are nearly straight, inflated and deflected slightly to the primary side. Striae are strongly radiate at the center in larger valves, becoming parallel at the distinct Voigt discontinuities and then convergent near the apices. The striae are more widely and irregularly spaced in the center of the valve. Areolae are very coarse and number 20-22 in 10 µm.

Autecology

Navicula streckerae has been recorded infrequently in creeks and rivers on the Northwestern Great Plains and Wyoming Basin (MT, ND, SD, WY), where it prefers warm waters rich in electrolytes and organic nutrients. Common diatom associates of N. streckerae on the Great Plains include Planothidium engelbrechtii, Navicula namibica, Entomoneis alata, Navicula peregrina, Tryblionella levidensis, Surirella striatula, Tryblionella gracilis, Tryblionella compressa, Hippodonta hungarica, Navicula salinarum, Gyrosigma macrum, Navicula curtisterna, Fallacia tenera, Amphora delicatissima, Fallacia pygmaea, and Biremis circumtexta. In Europe, N. streckerae was described from inland salt springs in the Weser River catchment and has also been found in marine habitats (Arctic Ocean) and in the estuary of the Weser River near Bremerhaven, Germany (Witkowski et al. 2000).

Original Description

Valvae stricte lanceolatae apicibus curte cuneatim (quoad specimina minora) vel distincte longius protractis paene subcapitatis (quoad specimina minora) polis semper obtuse rotundatis. Longitudo 26-55 microns, latitudo 8-10.5 microns. Fissurae externae internaeque raphis modice sed satis distincte laterales sitae fissuris esternis conspicue arcuatis cum poris cenralibus crassis ad latus primum valvae parum inclinatis (probabiliter sed non certe microscopo photonico). Area axialis angusta, area centralis saepe aliquantum variabilis ad instar plerumque transverse rectangularis vel elliptica vel rhombica. Striae transapicales fortius radiantes usque ad disordinationem Voigtii deinde subparallelae denque convergentes, 9-10 in 10 microns. Lineolae comparate crassae apparentes, 18-20 in 10 microns. Species nova plus minusve similis est speciebus diversis generis Navicula s. str. ut particulariter N. bourellyivera Lange-Bertalot et al. 1998, sed differt ad instar valvarum apicibus latius protractis et obtusius rotundatis item lineolis aliquantum distantius positis (18-20 versus 20-21 in 10 microns). Minus similis sunt: N. hanseatica, N. slesvicensis (illa est associata loco typico), N. pseudolanceolata, N. rhynchotella, N. kohlmaieri (vide supra et comparate in tabulis).

  • Author
    Lange-Bert. and Witkowski 2000
  • Length Range
    26-55 µm
  • Width
    8-10.5 µm
  • Striae in 10µm
    9-10

Original Images

Nstreck Origimage1
N Streck Origdesc1

Cite This Page

Bahls, L. (2011). Navicula streckerae. In Diatoms of North America. Retrieved July 23, 2018, from https://diatoms.org/species/navicula_streckerae

Responses

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