Effects of a mixture of non‐ortho‐ and mono‐ortho‐polychlorinated biphenyls on reproduction in Fundulus heteroclitus (Linnaeus)

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Abstract
To assess the effects of polychlorinated biphenyls (PCBs) on reproduction, female Fundulus heteroclitus were exposed to a mixture of non‐ortho‐ and mono‐ortho‐PCBs, mimicking the mixture found in fish collected from New Bedford Harbor, Massachusetts, USA, a PCB‐contaminated estuary. Exposure was by intraperitoneal injection of the mixture dissolved in corn oil. Doses of 0.76, 3.8, and 19 μg PCB mixture per gram of wet weight produced liver concentrations of 2.99, 12.2, and 32.8 μg non‐ortho‐and mono‐ortho‐PCBs per gram of dry liver, with dioxin toxic equivalency concentrations (TEQs) of 0.063, 0.409, and 0.720 ng/g, respectively. Female mortality was 58%, and egg production was reduced by 77% at the highest dose, compared to controls. Food consumption declined with increasing PCB concentration, suggesting that PCBs act indirectly to reduce fecundity through an energetic effect. Pituitary gonadotropin content appeared to be suppressed at the highest dose, but the ability of ovarian follicles to produce estradiol and testosterone in vitro was not impaired. Significant residue‐effects linkages were found, with TEQ emerging as a potential indicator of adverse effects. Mortality was directly related, and egg production was inversely related to log10TEQ. Multiple regression analysis indicated that egg production was directly related to pituitary gonadotropin content and food consumption.