Toxicity of Fintrol (Antimycin) and Prenfish (Rotenone) to Three Amphibian Species

Abstract

The toxicity of two piscicides, Fintrol® and Prenfish®, to Columbia spotted frogs (Rana luteiventris), long-toed salamanders (Ambystoma macrodactylum), and Rocky Mountain tailed frogs (Ascaphus truei) of varying life stages was detennined from 96-hr tests. The 96-hr LC50 values for Fintrol ranged from 13.7 to 192 μg/L, and for Prenfish the range was 0.009 to 9.65 mg/L. Tailed frog larvae were the most sensitive to both piscicides, surviving exposure to I· intro! as low as 3.7 μg/L, and having 10-percent mortality to the lowest test concentration of Prenfish tested (0.005 mg/L). Spotted frog adults survived exposure to Fintrol at concentrations six times the label prescription and survived exposure to Prenfish up to 4.5 times the label prescription. Long-toed salamander larvae survived exposure to Fintrol at levels -30 percent higher than the label prescription, but had a similar sensitivity to Prenfish as some species of fish. Comparing the results of these tests with tests on fish and other amphibians showed that when used in the field, Fintrol would likely not have an impact on any of the species or life stages tested, and Prenfish would not likely impact adult amphibians but could have an impact on larvae.