Description

SINGLE PAPER

Volume 14, Issue 3 – 10 July 2008

Kapil Mandrekar and Ronald G. Oldfield: Prior residency and social experience in contests between similar-sized juvenile black Midas cichlids, Amphilophus astorquii, pp. 141-148

Abstract
The possible roles of chemical cues and a 3-D structure in eliciting a prior residency effect in juvenile black Midas cichlids, Amphilophus astorquii, were tested under laboratory conditions. The effect of recent social interaction on the outcome of contests was also tested. Fish with a clay pot in their pre-test tanks defeated opponents without such prior experience when test tanks contained an identical pot. Experience in a small group of conspecifics had no significant effect on contest outcome, although fish that held lower size ranks tended to lose contests. The subjects’ chemical cues did not result in a prior residency effect. Interestingly, juvenile Amphilophus cichlids are not typically aggressive in their natural environment. The current results demonstrate that, despite this, they are sufficiently plastic to behave aggressively when resources are made to be defensible by artificially reducing attack distance and number of competitors. In addition, the ability to modify aggressive behavior according to prior experience demonstrates a further degree of plasticity. This suggests that complex behavioral plasticity relating to aggression may generally be of such high adaptive value that it might occur in species for which it might seem to typically have little utility.