9361

• UCREFRP Catalog Number: 9361
• Author: Beyers, D. W. and C. Sodergren.
• Title: Assessment and Prediction of Effects fo Selenium Exposure to larval Razorback Sucker.
• USFW Year: 1999.
• USFW - Doc Type: Project 95/CAP-6 SE,
• Copyright Material: NO

Physical and chemical conditions
Dilution water for the dietary study was supplied by a well on the Colorado State
University campus. Well water was treated by vigorous aeration for approximately 8 h while
being heated to a test temperature of 20 + 1°C. Alkalinity, hardness, pH, and specific
conductance were measured weekly; dissolved oxygen was measured daily; water temperature
was measured continuously. Dilution-water characteristics had the following ranges: dissolved
oxygen, 6.8 to 7.3 mg/L; alkalinity, 233 to 251 mg/L as CaCO3i hardness, 358 to 378 mg/L as
CaCO3; pH, 7.7 to 8.2; specific conductance, 750 to 850 µSfcm; and temperature, 19 to 22°C (see
Table A3 for other dissolved constituents).
The same dilution-water source was used for acute toxicity tests. Alkalinity, hardness,
pH, and specific conductance were measured at the beginning and end of the exposure period;
dissolved oxygen was measured daily; water temperature was measured continuously.
Dilution-water characteristics during acute tests had the following ranges: dissolved oxygen,
5.9 to 7.2 mg/L; alkalinity, 242 to 250 mg/L as CaCO3; hardness, 364 to 367 mg/L as CaCO3i
pH, 7.8 to 8.1; specific conductance, 750 to 830 µS/cm; and temperature, 20 to 21°C.
Toxicant solutions
A selenium stock solution was prepared by dissolving sodium selenate (NaZSeO4; Sigma
Chemical Company, St. Louis, Missouri) in dilution water. For the dietary study, concentrations
were prepared by delivering the stock solution to the diluter using a peristaltic pump. In
renewal-acute tests, exposure concentrations were prepared by pipetting the desired amount of a
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