Valves are linear to linear-lanceolate with parallel sides. The valve ends are well defined and capitate. The raphe is prominent and eccentric. Fibulae are distinct and parallel to the transapical axis. Interfibular spaces are rectangular to square, fibulae 8-11 in 10 µm. Striae are not visible with LM. This species is found in oligotrophic habitats.
Latin: ssp. dissipata differt valvis ad instar regulariter potius linearibus vel anguste lineari-lanceolatis nec latius lanceolatis item apicibus distincte capitulatis. Longitudo 30-45 µm, latitude 3-4 µm. Carina valde excentrica posita. Fibulae 8,5-11,5 in 10 µm. Striae transapicales vix discernandae in microscopo photonico, 46-48 in 10 µm. (in microscopo electronico).
German: Im Unterschied zu ssp. dissipata sind die Schalen regelmäßig linear bis schmal lineal-lanzettlich und die Enden sind (in geeigneter Lage sichtbar) deutlich kopfig vorgezogen. Länge 30-45 µm, breite 3-4 µm. Der Raphenkiel leegt stets starker sxzentrisch. Fibulae 8,5-11,5/10 µm, Streifen 46-48/ 10 µm.
From October 2011 until July 2019, this taxon appeared as Nitzschia dissipata subsp. oligotraphenta Lange-Bert. in Lange-Bert. and Metzeltin. The change of rank was published in Hofmann et al. (2011, pg. 453, Pl 109, Figs 3-7). As of this July 2019, the taxon is posted as N. oligotraphenta (Lange-Bert.) Lange-Bert. 2011.
- S. Spaulding
Manoylov, K. (2011). Nitzschia oligotraphenta. In Diatoms of North America. Retrieved December 03, 2024, from https://diatoms.org/species/nitzschia_oligotraphenta
The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Nitzschia oligotraphenta 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.