1Graduate School of Informatics, Kyoto University, Sakyo, Kyoto 606-8501, 2Ishigaki Tropical Station, Seikai National Fisheries Research Institute, Fisheries Research Agency, Ishigaki, Okinawa 907-0451, Japan
The effect of predator learning on the anti-predator performance of hatchery-reared black-spot tuskfish Choerodon schoenleinii was examined in the laboratory setting. We conditioned the tuskfish juveniles to predation by allowing them to sense their conspecifics being preyed upon by the predator Epinephelus merra. We then exposed the conditioned and naïve tuskfish to a predator. The conditioned fish approached nearby the predator's shelter (hazardous zone) earlier than the naïve fish, and the time to predation of conditioned fish was longer than that of the naïve fish. However, there was no significant difference in time to approach the hazardous zone between the conditioned and naïve fish when the predator was excluded from the tank. These results suggest that the pre-release predator learning treatment allows the hatchery-reared black-spot tuskfish to avoid approaching predators and decreases the post-release predation mortality.