The husbandry of the giant prawn Macrobrachium rosenbergii in geothermal - heated water was demonstrated to be successful at Oregon Institute of Technology. The feeding and care of this tropical prawn was accomplished in an outdoor raceway pond . The pond was not shielded from the ambient climate which during the winter months had recorded air temperatures as low as -20°C (-29°F) . The designed water temperature controlling apparatus and available heated water were found to be adequate to maintain a suitable environment for the prawns. This research is being sponsored by the Pacific Northwest Region Commission