National Research Institute of Fisheries Science, Fisheries Research Agency, Komaki, Ueda 386-0031, Japan
Individual differences in catchability of 65 largemouth bass by bait and lure fishing were investigated in an experimental pond. Ten fishing trials conducted every two days revealed that the number of bass caught on each day decreased in the later investigation days. The total number of times an individual bass was caught throughout the experimental period varied between zero and eight times, and there were three cases in which the same individual was caught twice on the same day. From the fishing record, 34 of the 65 largemouth bass were classified into careful (8), learnable (10) and fishable (16) individuals. These results indicate the existence of both learning of the danger of fishing and large individual differences in catchability by fishing and carefulness in largemouth bass.