Courtship behavior of male white perch, Morone americana: evidence for control by androgens

Courtship behaviors are androgen-dependent in many vertebrates and castrati on often decreases courtship. We examined the effectiveness of castration i n reducing courtship behaviors and 11-ketotestosterone (KT) and testosteron e (T) in restoring them in male white perch: Castrates were given implants containing KT, T or no hormone. Sham-operated males received implants witho ut hormone. Three weeks later, males were exposed to an ovulated female for 1 h and two courtship behaviors were quantified. Attending behavior involv es close and continuous following of a female with occasional contact. Circ ling involves rapid transits around the female in a circular pattern or bac k and forth in front of her. In plasma samples taken immediately after obse rvations, KT and T were below detectable levels in castrated males but at h igh physiological levels in males implanted with KT or T. Castrated males g iven KT attended females more than castrated males given T implants or impl ants containing no hormone, but not more than sham-operated males. Circling was eliminated by castration but restored by implantation with T or 11-KT to values exhibited by sham-operated males. This is one of the few demonstr ations that KT can regulate courtship behavior in a non-territorial and eco nomically important fish species. (C) 2001 Elsevier Science Inc. All rights reserved.