SOCIAL OVERSTIMULATION REDUCES SUBSEQUENT AGGRESSION IN BETTA SPLENDENS

This paper examines the waning of intense aggressive behaviors in Siam ese fighting fish subjected to continuous visual social stimulation. D amaging biting during subsequent fighting was dramatically reduced in fish which had been surrounded for several weeks by conspecifics, even though the overstimulated fish performed only opercular and fin displ ays to the fish surrounding them, not biting. The latency to opercular display was diminished, but the rate once opercular display began was not significantly different. In the 18 encounters observed, a sociall y overstimulated fish never dominated a control fish. This result sugg ests a visually mediated mechanism, which reduces biting tendency when there is prolonged, inescapable visual exposure to mildly aggression- releasing stimuli similar to those which trigger biting in live encoun ters. (C) 1994 Wiley-Liss, Inc.