EFFECTS OF DIETARY URANIUM ON REPRODUCTIVE ENDPOINTS-FECUNDITY, SURVIVAL, REPRODUCTIVE SUCCESS-OF THE FISH DANIO RERIO

Exposure to metal contaminated water has been shown to result in a number of reproductive abnormalities in adult and larvae fish such as failure of oocyte maturation and teratogenic effects Recently dietary uptake of metals by fish has been recognized as a critical route of exposure however the mechanisms of metal uptake and toxicity are poorly understood and in need of further investigation The objectives of the present study are to quantify uranium (U dietary transfers from spiked artificial diets) in Danio rerio tissues and embryos as well as establish its effect on reproduction and embryonic development Uranium s environmental prominence is currently increasing because of new mining and milling activities Uranium concentrations range from 0 02 mu g/L in natural waters to 2 mg/L The focus of this study was to examine the trophic transfer and effects of U following exposure modalities (dose exposure duration 1 to 20 d) Two different isotopes were used to distinguish between chemical and radioactivity toxicity of U Results showed that U trophic transfer was low (0 52%) Uranium tissue distributions showed that accumulation occurred in digestive organs (liver digestive tract) following dietary exposure High levels of U were measured in the gonads (female in particular >20% of relative burden) High U accumulation levels in eggs indicated maternal transfer of the contaminant Moreover U trophic exposure led to a reduction in reproduction success as a function of U accumulated levels High U exposure conditions strongly reduced the total number of eggs (50%) and their viability at 10 d (reduction of the clutch number low quality of eggs) Environ Toxicol Chem 2011 30 220-225 (C) 2010 SETAC