Survival and Immune Response of Coho Salmon Exposed to Copper.

摘要

Vaccination with Vibrio anguillarum by oral administration during copper exposure and intraperitoneal injection prior to copper exposure was employed to investigate the effects of copper upon survival and the immune response of juvenile coho salmon (Oncorhynchus kisutch). Following copper exposure the survivors were challenged under natural conditions to V. anguillarum,the causative agent of vibriosis in fish. Copper concentrations of 18.1micrograms/liter and higher caused significant mortality among coho fry during 30days of exposure. The exposure of copper bioassay survivors to a natural challenge against V. anguillarum in seawater caused significant mortality among those fish from concentrations of copper at 13.9micrograms/liter and higher. The reduced number of dead fish positive for V. anguillarum from the challenge suggests that sublethal copper stress and difficulty with seawater adaption may have caused several deaths. Significant mortality occurred among coho fingerlings exposed to 24.6micrograms/liter copper and higher for 31days. Most of the survivors of these concentrations were unable to adapt to seawater and died within the first three days of challenge.