• Category
  • Length Range
    23-36 µm
  • Width Range
    4.1-5.4 µm
  • Striae in 10 µm
    18-22 dorsal, 20-25 ventral

Identification

Description

Valves are lunate with a moderately arched dorsal margin and a concave ventral margin that is tumid in the middle. Apices are narrow and rounded. The axial area is narrow and displaced ventrally. A central area is absent. The raphe is lateral, becoming distinctly reverse-lateral near the proximal ends, which are displaced ventrally. Terminal raphe fissures are comma-shaped and bent dorsally. Striae are radiate throughout and shorter on the ventral side of the axial area.

Autecology

Delicata canadensis was found in five water bodies along the Coppermine and Baillie Rivers, in Nunavut, Canada, where pH ranged from 7.1 to 8.3. In Bloody Falls Tundra Lake (photo below) it was associated with a substrate of iron oxide precipitates.

September Mountains Lake
Credit: Beverly Boynton
September Mountains Lake, Nunavut, Canada.
Bloody Falls Tundra Lake
Credit: Beverly Boynton
Bloody Falls Tundra Lake, Nunavut, Canada.
Bloody Falls Tundra Lake Closeup
Credit: Beverly Boynton
Close-up of iron oxide precipitates on bottom of Bloody Falls Tundra Lake.

Original Description

Valves are narrow, lanceolate and lunate with a moderately arched dorsal margin and a concave ventral margin that is tumid in the middle. Apices are narrow and rounded. Valve length 23-36 µm; valve width 4.1-5.4 µm. The axial area is narrow and displaced ventrally. A central area is absent. The raphe is lateral, becoming distinctly reverse-lateral near the proximal ends, which are also displaced ventrally. Terminal raphe fissures are comma-shaped and bent dorsally. Striae are radiate throughout and shorter on the ventral side of the axial area. Striae number 18-22 in 10 µm on the dorsal side, 20-25 in 10 µm on the ventral side (measured in a 10 µm segment adjacent to the central area). [n=26]

  • Author
    L.L. Bahls 2017
  • Length Range
    23-36 µm
  • Width
    4.1-5.4 µm
  • Striae in 10µm
    18-22 dorsal, 20-25 ventral

Original Images

Delicata Canadensis
Delicata Canadensis Wholevalve
Delicata Canadensis Externalmiddle

Cite This Page

Bahls, L. (2017). Delicata canadensis. In Diatoms of North America. Retrieved July 18, 2019, from https://diatoms.org/species/delicata_canadensis

Responses

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