Effects of in situ selenium exposure and maternal transfer on survival and deformities of brown trout (Salmo trutta) fry.

Offspring of wild adult brown trout exposed to a range of Se concentrations were reared in a laboratory setting to primarily assess effects on survival and deformities. Maternal whole-body Se concentrations ranged from 4.7 to 22.6 mg/kg dry weight for wild fish. Corresponding Se concentrations in embryos ranged from 6.2 to 40.3 mg/kg dry weight. Significant relationships were found between embryo and whole-body tissue concentrations. Increasing egg Se concentrations were correlated with decreasing survival; however, hatch success was not significantly correlated with increasing embryo Se. The best fit effect concentration, 10% (EC10) for survival in the hatch to swim-up period was 20.6 mg/kg dry weight, and the EC10 for hatch to test termination at 88 d was 20.5 mg/kg dry weight egg Se. The best fit model for deformities was based on a baseline-adjusted severity index and resulted in an EC10 of 21.8 mg/kg dry weight egg Se. Both the best fit model EC10s represent more sensitive values than the published range of trout species EC10s. An egg to whole-body tissue conversion factor derived from the paired data resulted in a conversion factor for brown trout of 1.46, which resulted in a whole-body tissue EC10 of 14.04 mg/kg dry weight at an egg tissue EC10 of 20.5 mg/kg dry weight. Environ Toxicol Chem 2018;37:1396-1408. © 2018 SETAC.