Effects of Copper Sulfate on Growth, Development, and Escape Behavior in Epidalea calamita Embryos and Larvae

Epidalea calamita embryos at Gosner stages 3 and 19, and larvae at Gosner stage 25, were exposed to different copper sulfate concentrations, ranging from 0.05 to 0.40 mg Cu L-1, in 96-h acute toxicity tests. Embryonic and larval mortality, development, growth, and larval escape behavior were evaluated. LC50 at 96 h obtained at Gosner stages 3, 19, and 25 were 0.22, 0.08, and 0.11 mg Cu L-1, respectively. Embryonic and larval developments were delayed after 96 h of copper sulfate exposure. Growth was also affected and individuals in control treatments grew to twice the size of those exposed to copper concentrations over 0.2 mg Cu L-1 during the experiments initiated at Gosner stage 19. Escape behavior was altered after 96 h of copper sulfate exposure; larvae showed shorter distances moved and abnormal displacement types. However, after 4 days of recovery process, most of the larvae showed normal escape behavior. For amphibians that develop in temporary wetlands, increased development time, lower size, and altered escape behavior might have repercussions on the number of individuals that can successfully complete metamorphosis and, consequently, on recruitment.