BEHAVIORAL-TESTS FOR MAGNETIC SENSITIVITY OF HIME SALMON (KOKANEE - LAND-LOCKED SOCKEYE-SALMON ONCORHYNCHUS-NERKA)

Juvenile and mature hime salmon were tested for their magnetic sensiti vity using a successive conditioning. Fifty juvenile fish were reinfor ced according to concurrent changes of intensity, direction, and incli nation of the magnetic field as a conditioned stimulus and an electric shock as an unconditioned stimulus. Twenty mature fish were reinforce d according to an alternative magnetic field which-rotates the horizon tal component of the magnetic field in the tank through 120 degrees at 1 Hz. The intensity of the total magnetic field in the tank was also changed from 0.56 to 0.80 gauss. Cumulative number of training reached 300 times for juvenile fish and 600 times for mature fish. No statist ically significant conditioned reflex was observed in either juvenile or mature fish. However, the other fifty juvenile fish and twenty matu re fish were successfully conditioned by lighting stimulus (100 simila r to 130 1x for juvenile fish and 20 similar to 25 1x for mature fish) instead of the magnetic stimulus. These results indicate that hime sa lmon may not have magnetic sensitivity.