Androgen receptor antagonist impairs courtship but not aggressive behavior in the monogamous cichlid, Amatitlania nigrofasciata

Androgens, specifically 11-ketotestosterone, are hypothesized to be important in the expression of pre-spawning behaviors such as courtship and aggression in many teleost species. This experiment attempted to elucidate the roles of androgens in the expression of pre-spawning courtship and aggression in male convict cichlids (Amatitlania nigrofasciata). In a laboratory experiment, males were treated with either the androgen receptor antagonist flutamide or blank control and subsequently exposed to social conditions to stimulate inter-sexual courtship or intra-sexual aggression. Males treated with flutamide expressed significantly fewer courtship behaviors than control males but did not differ from control males in pre-spawning intra-sexual aggression. In a field experiment, males treated with flutamide expressed significantly less courtship behavior than males given blank capsules or unmanipulated control males, but did not differ from either set of control males in aggression towards conspecifics or overall aggression to con- and heterospecifics. These data suggest that androgens mediate pre-spawning courtship behavior but not pre-spawning aggression in this species.

► Male convict cichlids were treated with flutamide to block action of androgens
► Flutamide inhibited pre-spawning courtship but not intra-sexual aggression
► Results of laboratory experiment were validated and strongly supported by similar results in field experiment
► Results suggest that under these conditions androgens play a role in courtship but not aggressive behavior