FURTHER STUDIES OF THE AGGREGATING BEHAVIOR OF AMEIURUS MELAS

Abstract

Responses of the young of these catfishes to stones and to one another indicated that there is no gustatory stimulus acting in aggregating them. Isolation for 20 days broke down the positive responses of blinded catfishes to one another when passing within a distance of 2 in. With normal individuals the positive sight response was decreased after longer periods of isolation. In both cases positive reactions were reestablished soon after contact occurred, a fact which emphasizes the importance of the thigmotactic stimulus. No difference in O consumption over hour periods was found between grouped and isolated individuals, probably due to the greater activity of the group which in other species has a lower respiratory rate.