Species Differences in Long-Term Discriminated Avoidance in Fish

Summary

Four species of fish (N =12 each)—goldfish (Carassius auratus), mollies (Mollienesia sphenops), swordtails (Xiphophorus helleri), and gouramies (Helostoma temmincki)—were given 20 trials a day of avoidance conditioning to a visual CS in an aquatic shuttlebox for a minimum of 12 days and continuing to 30 days until a criterion of 17 avoidances in 20 trials had been reached. Species differences in trials to reach criterion reflected the number of fish within each species which failed to reach criterion. While all goldfish reached criterion quickly, a few swordtails required many trials, and some mollies and gouramies did not reach criterion in 30 days.