EFFECTS OF THE PLANAR PCB 3,3',4,4'-TETRACHLOROBIPHENYL (TCB) ON OVARIAN DEVELOPMENT, PLASMA-LEVELS OF SEX STEROID-HORMONES AND VITELLOGENIN, AND PROGENY SURVIVAL IN THE WHITE PERCH (MORONE-AMERICANA)

Adult white perch were given three intraperitoneal injections of 3,3', 4,4'-tetrachlorobiphenyl (TCB) at one of three different doses (0.2-5. 0 mg TCB/kg body weight). The TCB injections were initiated approx. 3 months prior to the spawning season and given at 3-week intervals. Few er females matured in the group receiving the highest dose of TCB. Tho se fish that did mature had a gonadal somatic index approximately half that of control females. Circulating levels of the sex steroid hormon es, estradiol-17beta and testosterone, and of the egg yolk precursor, vitellogenin, were not significantly altered by TCB exposure. By 7 day s post-hatch survival of larvae produced from females exposed to 1.0 a nd 5.0 mg/kg TCB was reduced as compared to controls (0, 1 and 54%, re spectively). These results show that: (1) TCB impairs both maturation of adult females and survival of their offspring, and (2) decreased la rval survival may occur at TCB doses less than those required to decre ase ovarian growth, oocyte maturation, or circulating sex steroid horm one and vitellogenin concentrations in the adult fish.