The effect of testosterone on the behavior and coloration of adult male cichlid fish (Haplochromis burtoni, Günther).

The African cichlid fish Haplochromis burtoni shows specific behavioral responses to the intramuscular injection of testosterone. Approaching and attacking were significantly increased by injections, while six other observed behaviors remained unchanged. The results suggest that the injected testosterone affected the control of both sexual and agonistic behaviors.