Friday January 15, 2010
Can’t teach an old fish new tricks? Maybe that depends on the fish. In a study that included several common fish species introduced to California, Coble and colleagues found that fish vary in how well they learn. In this experiment, different species of fishes were placed in a small box divided by a piece of wood, and were trained to move to the other side of the box in response to light to avoid an electrical shock. Striped bass, common carp and channel catfish were the ‘best students’, while yellow perch and bluegill ranked nearly last out of 14 species. It is important to note, however, that for some species that are generally slow moving, bottom dwellers, the natural reaction to a stimulus such as light may be to freeze, rather than move, making it appear that they are poor learners.
While older channel catfish chose the correct response significantly more often than juvenile catfish, there was no difference in the percent of correct responses for older and younger largemouth bass. It is interesting to note that some of the species preserved their learned behavior for months.
Graph adapted from Coble, D. W., G . Farabee, and R. Anderson. 1985. Comparative learning ability of selected fishes. Can. J. Fish. Aquat. Sci. 42: 791-796.