Interaction of chemical pollutants and virus in a crustacean: a novel bioassay system

A large group of shrimp, 23.3% of which had light patent Baculovirus infections, was divided equally into two groups. One group was exposed to the chemical stressor Aroclor 1254 (a polychlorinated biphenyl) at 0.7 ppb for 35 days in flowing seawater. The other group was maintained as a control group in flowing seawater. Viral prevalence in exposed shrimp samples increased with time at a significantly greater rate than did viral frequency in control shrimp. Viral prevalence in Aroclor-exposed shrimp survivors was 75% after 35 days, whereas in control shrimp, only 45.7% had patent viral infections. This finding suggests an interaction among chemical stressor (Aroclor 1254), host, and virus. The nature or mechanism of this interaction has not been defined, but the shrimp-virus system shows, promise for future bioassays of influence of low concentrations of pollutants on natural pathogenhost interactions.