Dissociação entre observação e interação na modificação do display agressivo do Betta splendens

The observation of fight (i.e., the presence of an anonymous observer of a fight) is something that changes the parameters of the fighting display of Betta splendens. The aim of this study was to identify whether and how observation alone or associated with the interaction modifies the emission of the display. Male Betta splendens were used (N = 28) in a battery of experiments to identify whether the aggressive display is modified either by the observation of a conspecific in a situation of confrontation (Experiment I) or by the observation of a conspecific in a situation of confrontation and subsequent exposure to this very conspecific (Experiment II). There was no statistical difference in the data obtained from the Experiment I, however, with respect to the data obtained in the Experiment II we could identify a statistically significant difference (F (1.6) = 6.002, p = 0.05) reflected in an increased latency of the Horizontal Display. We concluded that in Experiment I the behaviors were stable, and that the observation associated with interaction (Experiment II) is able to modify the emission of the aggressive display of Betta splendens.