ON THE PREDICTABILITY, SENSITIZATION, AND HABITUATION OF AGGRESSION IN MALE BETTAS (BETTA SPLENDENS)

The winners of dyadic contests between male bettas (Betta splendens) w ere fish that in a 30-min prefight test spent a greater amount of time approaching a conspecific male that was confined behind clear glass. Approach duration was shown also to be a stable characteristic over pe riods as long as 30 days. Finally, approach durations and fight outcom es were influenced by both prior fighting and exposure to conspecifics behind glass. The nature of this influence, however, was dependent on the duration of an animal's approach duration in a 1/2-hr pretreatmen t test. Fish with low approach durations were influenced far more exte nsively by social experiences than were animals with high approach dur ations. These studies are discussed with reference to theories of oppo nent assessment and the habituation and sensitization of aggression an d in the context of some ethically phrased criticisms previously direc ted at investigations of aggression and predation.