Influence of high temperature on cadmium-induced skeletal deformities in juvenile mosquitofish (<Emphasis Type="Italic">Gambusia affinis</Emphasis>)

The aim of this study was to assess the effect of high temperature on cadmium (Cd)-induced skeletal deformities in juvenile Mosquitofish, Gambusia affinis. For this purpose, 188 juveniles (1 day old) were equally divided into the control group, which was maintained in Cd-free water at 24°C, and three treated groups exposed either to Cd (0.4 mg/l as Cd Cl₂) at 24°C, to high temperature (32°C), or to Cd at 32°C for 30 days. The results showed that Cd exposure at 24°C significantly increased the Cd accumulation (P < 0.0001) in the whole tissues of juveniles as well as the incidence of skeletal deformities (P < 0.01) compared with control animals. Exposure to high temperature also led to a significant increase in the incidence of skeletal deformities (P < 0.01) with respect to the control group. Interestingly, our results showed that the combined exposure to Cd and high temperature led to a more significant increase in Cd accumulation and in the frequency of spinal deformities than exposure to Cd or high temperature alone. These results confirm that temperature increases Cd toxicity and needs to be taken into account for the accurate prediction and assessment of Cd-induced spinal deformities in fish.