All animals used in these studies were sourced from a colony of B. marinus maintained at CSIRO according to the methods described in Hamilton et al. [19] . Briefly, when tadpoles were required, adults were injected subcutaneously with a 0.25 mg/mL solution of leuprorelin acetate to induce ovulation and stimulate amplexus. Eggs were hatched and tadpoles maintained in aged water without chlorine at a temperature of 23-27uC.