Embry otoxicity and Teratogenicity of Cu and Zn2+ for Xenopus laevis, Assayed by the FETAX Procedure*

Cupric chloride (CuCl2) and zinc chloride (ZnCl2) were tested by the FETAX (Frog Embryo Teratogenesis Assay: Xenopus) procedure in the South African frog, Xenopus laevis. The median teratogenic concentrations (EC50) of Cu2+ and Zn2+ were 2.5 and 40 jjunol per L. The median embryo-lethal concentrations (LC50) of Cu2+ and Zn2+ were 22 and 850 fjimol per L. The teratogenic indices (TI = LC50/EC 50) were 8.8 for Cu2+ and 21 for Zn2 +. Both metal ions were shown to be potent teratogens for Xenopus, causing concentration-related increases of eye, gut, facial, notochord, and cardiac anomalies