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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Monopylephorus cuticulatus

Salt-water species. (ref. ID; 7006)

[ref. ID; 6604]

Test system

Sublethal toxicity

Strains

Worms were collected intertidally from the mouth of Union Bay Creek, Patricia Bay, B.C. This area is free from any significant industrial pollutant inputs.

Toxicants

Sediment samples were collected from a total of 97 stations in Puget Sound. At all stations with the exception of Birch Bay (where intertidal collections were made by scooping up sediment), subtidal sediment was collected using a Van Veen grab modified with top screens. Sediments to a depth of 6 cm were removed from the grab with a clean scoop, placed in polyethylene bags and immediately homogenized by careful and thorough kneading. The bags were then sealed, transported on ice, and maintained at 4 degrees C in the dark prior to testing (a maximum of 6 weeks).

Test design

Sediments from each sampling station were homogenized and mixed with clean sea water (25 ppt salinity) to yield a 20,000 mg/L weight/volume sediment/water slurry. The slurry was then centrifuged at 1,000 rpm for 10 min and the resulting elutriate decanted and used at the test medium.
Worms placed in syringes containing test elutriate. The syringes were carefully capped to exclude all air bubbles, and incubated upside-down in a darkened water bath (10+/-0.5 degrees C) for 1 hr. Duplicate + blank.

Measurements

Oxygen measurement, dry weight.

Evaluations

Respiration rates uL O2/hr/mg dry weight.

[ref. ID; 7006]

Test system

96-hr acute lethal bioassay

Strains

Worms were sieved (0.5 mm mesh) from sediment (Patricia Bay, B.C.) collected by means of Ponar grabs or dip nets.

Toxicants

3CdSO4/8H2O, HgCl2, 2,3,4,5,6-Pentacholophenate, and black liquor.

Test design

Petri dishes (3.5 cm diameter and 1 cm depth). Loading densities <0.5 g/L. 24-hr solution replacement. 3 replicates. Dark.

Experimental condition

Temperature (1, 10, 20 degrees C), pH (6, 7, 8), salinity (10, 20 ppt).

Measurements/observations

Mortality.

Evaluations

LC50.