Social organization and the maintenance of aggressive behavior in community-housed male Siamese fighting fish (Betta splendens)

The waning of aggressive behavior in two groups of community-housed maleBetta was studied by observing incidences of display and fighting behaviors. In Experiment 1, observations were made during the establishment of a community, while it was maintained at a stable size, and during systematic removal of the dominant (alpha) males. Experiment 2 investigated the aggressive interactions of males in a stable-sized population, maintained for a period of 10 weeks. The results indicate that prolonged periods of constant conspecific exposure do not necessarily result in a significant attenuation of display behaviors. The data further indicate that the social organization (as determined from aggressive interactions) appears to be one in which the top- and bottom-ranking males are clearly defined. It is suggested that the maintenance of aggressive behavior among community-housed maleBetta may well be related to their social position.