Delicatophycus canadensis | Species - Diatoms of North America

Category

Asymmetric Biraphid
Length Range

23-36 µm
Width Range

4.1-5.4 µm
Striae in 10 µm

18-22 dorsal, 20-25 ventral

Contributor

Loren Bahls - May 2017
Reviewer

Sarah Spaulding - Oct 2018

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Identification

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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

This taxon 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.

Size Range, µm3

101-1000
Motility

Moderately motile
Attachment

Unattached
Habitat

Benthic
Colony

Solitary
Occurrence

Rare
Waterbody

Inland Lakes
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Credit: Beverly Boynton

September Mountains Lake, Nunavut, Canada.

Credit: Beverly Boynton

Bloody Falls Tundra Lake, Nunavut, Canada.

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

Citations & Links

Citations

Updates

Aug 21, 2023 - Transfer from Delicata to Delicatophycus

From October 2018 to August 2023, this taxon appeared as Delicata canadensis Bahls 2017. Following Wynne (2019) the name Delicatophycus canadensis M.J.Wynne 2019 is a replacement name. - S. Spaulding

Cite This Page

Bahls, L. (2017). Delicatophycus canadensis. In Diatoms of North America. Retrieved December 21, 2024, from https://diatoms.org/species/52258/delicatophycus_canadensis

Responses

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