The effect of polychlorinated biphenyl on steroidogenesis and reproduction in the brook trout (Salvelinus fontinalis).

Livers from brook trout (Salvelinus fontinalis) held in water containing 3.8 p.p.m. (mg/l) Corexit and in water containing 3.8 p.p.m. Corexit + 0.2 p.p.m. polychlorinated biphenyl (PCB) were firmer in texture than livers taken from control trout held in fresh water. The testes from the PCB-treated trout were darker in color, smaller in size, contained less spermatic fluid, and appeared to be regressed when compared with testes from the control fish. Only 72% of the eggs from PCB-treated trout hatched compared to 92% for control eggs when eggs were incubated in fresh water. Fertilized eggs incubated in water containing 0.2 p.p.m. PCB + 3.8 p.p.m. Corexit resulted in less than 1% of the eggs from the untreated fish and none of the eggs from PCB-treated fish being hatched. The young fish from the control group lived only a few days in the water containing PCB. PCB greatly stimulated the in vitro 11beta-hydroxylation of testosterone by trout testicular tissue. There was no significant change in 11-ketotestosterone blood levels in maturing brook trout after treatment with 3.8 p.p.m. Corexit or 3.8 p.p.m. Corexit + 0.2 p.p.m. PCB for 21 days during the final stages of maturation. It is thought that sublethal levels of PCB can interfere with the reproduction process in this species.