Effects of Silver on Eggs and Larvae of the Winter Flounder

Abstract

Embryos and yolk-sac larvae of the winter flounder Pseudopleuronectes americanus were exposed to 0 (control), 54, 92, 180, and 386 μg/liter silver (Ag +) during an 18-day flow-through bioassay. Percent hatch was significantly reduced only at the 386-μg/liter exposure level (24%). Embryos exposed to 180 and 386 μg/liter hatched earlier than those exposed to lower concentrations, and many exhibited physical abnormalities. Larva mortality was significantly higher at 386, 180, and 92 μg/liter (100, 97, and 31%, respectively) than in the control (6%). The mean total lengths of larvae at hatch were significantly greater in control (3.56 mm) than in 386 μg/liter (1.98 mm) and 180 μg/liter (3.25 mm). At yolk-sac absorption, the mean total length of control larvae (4.27 mm) was significantly greater than that of larvae exposed to 180 μg/liter (4.15 mm). The highest concentration of silver not significantly reducing either survival or growth was 54 μg/liter.