Faculty of Fisheries, Kagoshima University, Kagoshima, Kagoshima 890-0056, Japan
A stimulus generalization paradigm was used with classical conditioning to sound to examine the ability of discrimination of sound frequency in nonostariophysine fishes. Groups of two marine teleosts, red sea bream Pagrus major and horse mackerel Trachurus japonicus, were conditioned for food on the presentation of a complex sound comprised of two sinusoidal components, 313Hz and 700Hz. Conditioned groups were then presented with a set of 12novel tones with frequencies between 100Hz and 2000Hz, including 300Hz and 700Hz. Response magnitudes were greatest at 300Hz and 700Hz in the two fishes, implying that these two nonostariophysine fishes had analytically listened to the frequencies of the individual sinusoidal components making up the complex sound to which the fishes had been initially conditioned.