Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, Ontario, Canada.
Horm Behav. 2010 Sep;58(4):599-605. doi: 10.1016/j.yhbeh.2010.06.016. Epub 2010 Jul 6.
Proximate mediators of reproductive behaviors in vertebrates have a long history of study. In fishes, relatively few studies have focused on hormonal control of parental care, despite a comprehensive background on the general physiology of fishes, and the frequent occurrence of parental care behaviors. Studies on this taxon have repeatedly found that the relationships between androgens and paternal care do not follow the predictions made in the avian and mammalian literature. Glucocorticoids may also have a role in mediating parental behaviors, possibly through their role as regulators of metabolism. As such, we investigated the role of 11-ketotestosterone (11-KT) and cortisol in mediating parental effort of male smallmouth bass (Micropterus dolomieu) by manipulating hormone titers in wild fish. In smallmouth bass, males spawn annually with a single female and defend a single brood for up to 30 days. Treatment of parental fish with cyproterone acetate (CYA; an androgen receptor antagonist) resulted in a decrease in nest defense in response to a simulated brood predator; however, no changes in nest success, nest tending or biochemical indicators of nutritional status were detected. Treatment with exogenous cortisol did not change parental behavior, but did increase the rate of nest failure, possibly owing to the energetic cost of chronically elevated cortisol concentrations. We discuss these findings in the context of resource-driven trade-offs and highlight life history as an important factor controlling parental effort in species with costly parental care behaviors.
脊椎动物生殖行为的近因中介物已有很长的研究历史。在鱼类中，尽管鱼类生理学的综合背景和普遍存在的亲代养育行为，但相对较少的研究集中在荷尔蒙对亲代养育的控制上。对该分类群的研究反复发现，雄激素与亲代养育之间的关系与鸟类和哺乳动物文献中的预测并不一致。糖皮质激素也可能在介导亲代行为中发挥作用，可能是通过其作为代谢调节剂的作用。因此，我们通过操纵野外鱼类的激素水平，研究了 11-酮睾酮（11-KT）和皮质醇在介导小口黑鲈（Micropterus dolomieu）亲代努力中的作用。在小口黑鲈中，雄性每年与一只雌性交配，并为一只幼鱼守护长达 30 天。用醋酸环丙孕酮（CYA；雄激素受体拮抗剂）处理亲鱼会导致对模拟幼鱼捕食者的巢防御减少；然而，没有检测到巢成功率、巢护理或营养状况的生化指标发生变化。用外源性皮质醇处理不会改变亲代行为，但会增加巢失败的速度，这可能是由于长期升高的皮质醇浓度的能量成本。我们在资源驱动的权衡背景下讨论了这些发现，并强调了生活史作为控制具有昂贵亲代养育行为的物种亲代努力的重要因素。
