Department of Biology, University of Western Ontario, London, ON N6A 5B7, Canada.
Annis Water Resources Institute, Grand Valley State University, Muskegon 49441, MI, USA.
Horm Behav. 2019 Nov;116:104582. doi: 10.1016/j.yhbeh.2019.104582. Epub 2019 Sep 4.
Parental care can include two general types of behavior: (1) aggressive behavior, which is used to defend offspring from predators; and (2) nurturing behavior, which is used to provide offspring with environmental conditions or resources necessary for survival. Many studies have implicated androgens in promoting aggressive behavior and prolactin in promoting nurturing behavior. We experimentally manipulated these hormones to investigate their effects on parental care behavior in bluegill (Lepomis macrochirus). Parental males, which provide sole care to the developing eggs and larvae, received an implant with an androgen (11-ketotestosterone [11-KT]), an androgen antagonist (flutamide), prolactin, a prolactin-release inhibitor (bromocriptine), or castor oil (placebo). We found that 11-KT implants led to a significant increase in the frequency of aggressive behavior directed towards a simulated brood predator, and were associated with a nearly significant decrease in the frequency of nurturing behavior directed towards the developing eggs. In contrast, prolactin implants were associated with a significant increase in the frequency of nurturing behavior, but also reduced the frequency of aggressive behavior directed towards the simulated brood predator. These results suggest a hormone-mediated mechanistic trade-off between nurturing and aggressive behavior, whereby parental males are unable to be both highly nurturing and highly aggressive.
（1）攻击行为，用于保护后代免受捕食者的侵害；（2）养育行为，用于为后代提供生存所需的环境条件或资源。许多研究表明雄激素促进攻击行为，催乳素促进养育行为。我们通过实验操纵这些激素，以研究它们对蓝鳃太阳鱼（Lepomis macrochirus）亲代照顾行为的影响。亲代雄性独自照顾发育中的卵子和幼虫，接受了雄激素（11-酮睾酮[11-KT]）、雄激素拮抗剂（氟他胺）、催乳素、催乳素释放抑制剂（溴隐亭）或蓖麻油（安慰剂）的植入物。我们发现，11-KT 植入物导致了针对模拟育雏捕食者的攻击行为的频率显著增加，并且与针对发育中的卵子的养育行为的频率显著降低有关。相比之下，催乳素植入物与养育行为的频率显著增加有关，但也降低了针对模拟育雏捕食者的攻击行为的频率。这些结果表明，在养育和攻击行为之间存在激素介导的机制权衡，即亲代雄性不能同时高度养育和高度攻击。
