Repeated Recent Aggressive Encounters Do Not Affect Behavioral Consistency in Male Siamese Fighting Fish

Abstract

Consistent individual differences in behavior suggest that individuals respond in a predictable and repeatable manner in a specific situation while differing from other individuals. Male Siamese fighting fish exhibit consistent individual differences in decision-making strategies when they encounter a receptive female and a rival male simultaneously. However, whether these differences are altered by recent experience is unknown. We examined the influence of repeated aggressive encounters on behavioral consistency and decision-making. Males were presented with paired female–male dummies prior to any aggressive experiences to obtain a baseline measure. Next, males either won or lost three consecutive contests against rivals and then received the paired female–male dummies after each of these encounters. Overall levels of highly aggressive behaviors were affected by contest outcome, while levels of female-directed were not. Not surprisingly, winning a fight led to an increase in male-directed bites, an overtly aggressive behavior that only occurs after fights have escalated. Fighting a male before encountering the dummies caused males to perform more tail beats to the dummy male, perhaps as a result of increased motivation. Males exhibited similar levels of repeatability and used the same strategies when faced with conflicting stimuli regardless of fighting experience. Thus, while winning or losing a fight impacts overall aggression, it does not influence behavioral consistency. This study demonstrates that consistent individual differences and decision-making strategies may be resistant to recent aggressive experiences, even over a period of days.