Valves are linear-lanceolate and weakly dorsiventral, with rounded apices. The dorsal margin is arched; the ventral margin is nearly flat. The axial area is very narrow. The central area is small and elliptic, or absent. The raphe is weakly lateral with ventrally deflected proximal ends and dorsally deflected terminal ends. The proximal raphe ends are simple and not expanded. Striae are radiate throughout.
This taxon lacks stigmata and the strongly dorsiventral valves that are characteristic of the genus Cymbella.
This taxon has been collected from two alkaline (pH 8.17 and 8.30) lakes on the tundra in northern Canada. Both lakes are on the Canadian Shield in the catchment of the Coppermine River. The lakes (photos below) have substrata composed of ferric hydroxide floc, formed when dissolved iron is complexed in the presence of organic matter (peat).
Valves are linear-lanceolate and weakly dorsiventral with rounded apices. The dorsal margin is arched; the ventral margin is nearly flat. Valve length 21-32 μm; valve width 4.2-4.9 μm. The axial area is very narrow; the central area is small and elliptic or absent. The raphe is weakly lateral with ventrally deflected proximal ends and dorsally deflected terminal ends. Striae are radiate throughout, 17-21 in 10 μm at the valve center, up to 28 in 10 μm at the apices. [n=10]
From January 1, 2019 to March 18, 2024, this taxon appeared on diatoms.org as Cymbopleura tundraphila Bahls 2017. Following the transfer to Delicatophycus (Edlund et al. 2024), it now appears as D. tundraphilus (Bahls) Edlund 2024.
Bahls, L. (2018). Delicatophycus tundraphilus. In Diatoms of North America. Retrieved December 02, 2024, from https://diatoms.org/species/delicatophycus-tundraphilus
The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Delicatophycus tundraphilus 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.