THE INFLUENCE OF OPPONENT-RELATED AND OUTCOME-RELATED MEMORY ON REPEATED AGGRESSIVE ENCOUNTERS IN THE PARADISE FISH (MACROPODUS-OPERCULARIS)

The aggressive behavior of male paradise fish (Macropodus opercularis) was studied. Fish were subjected to three aggressive encounters on co nsecutive days. If submissive males encountered the same opponent thre e times, the last aggressive encounter was very different than the fir st one. When the animals faced a new opponent each day, the changes we re much less pronounced. We conclude that (1) fish are able to recogni ze their opponents at least one day after the encounter (''social reco gnition''), and (2) social recognition modifies the effect of prior de feat (''status-related memory'') in subsequent encounters.