Effects from a short-term exposure to copper or cadmium in gravid females of the livebearer fish (Gambusia affinis).

We investigated the reproductive effects of a 10-day maternal metal exposure in the live-bearing western mosquitofish. We exposed gravid females to 0.15µM copper or cadmium and monitored reproduction-related variables over the subsequent 8-month breeding season. Females gave birth to 1-5 broods, a number not affected by the exposure. Their first brood's size was reduced following exposure to either metal, while this effect was still evident for the second brood of copper-exposed females. Metal-exposed females also had more premature births, abortions, and broods containing dead offspring; these last two effects were still evident in second broods. The time-till-first-birth was reduced while the time-interval between first and second brood was increased in cadmium-exposed females, but not in copper-exposed ones. This study demonstrated that short-term metal exposure affects a variety of reproductive measures and that effects can still occur in broods that developed well after the end of the females' exposure.