Before Otway rears grey nurse sharks, his crew will study and duplicate the intrauterine solution found in the mothers. Then he'll build separate wombs for each embryo. If all goes well with the 10-year project, he could increase a mother's brood to 20. Otway says he could adapt the device for biologically similar species, but he has no plans to make artificial human uteresus. "That might be possible, but I don't want to get into it because of the ethical issues," he says. "I'll stick with sharks."