This study outlines an investigation into the feasibility of an immunologically based biocontrol for cane toads. We demonstrate the presence of a clear larval to adult switch in haemoglobin mRNA and protein levels and hypothesise that this switch may be affected by early exposure, by either injection or viral delivery, to adult B. marinus haemoglobin. Our results indicate that the altered adult globin protein profile seen in Rana catesbeiana metamorphs after exposure of tadpoles to adult globin does not occur in B.marinus. The short larval stage in B. marinus compared with R. catesbeiana may preclude this approach to cane toad biocontrol.