Endocrine Changes Associated with Spawning Behavior in Male Kokanee Salmon (Oncorhynchus nerka) and the Effects of Anosmia
Endocrine Changes Associated with Spawning Behavior in Male Kokanee Salmon (Oncorhynchus nerka) and the Effects of Anosmia
复制标题
与雄性科卡尼鲑鱼 (Oncorhynchus nerka) 产卵行为相关的内分泌变化以及嗅觉丧失的影响
作者：
N. Liley;K. Olsén;C. Foote;G. VanDerKraak
本研究探讨社会地位之间的关系，行为活动和激素水平通过产卵周期在男性kokanee鲑鱼（Oncorhynchus nerka）。到达产卵场后不久，雄性科卡尼在形态和生理条件上发生了巨大的变化：身体深度增加，明亮的银色外观被强烈的红色所取代，精子开始产生。雄企鹅与筑巢的雌企鹅有联系，它们保护雌企鹅不受其他雄企鹅的侵害。雄激素，睾酮和11-酮睾酮，在产卵期间从银色雄性中观察到的高水平缓慢下降;促性腺激素（GtH II）和17 α，20 β-二羟基-4-异戊烯-3-酮随着雄性接近最终成熟而增加。雄激素和GtH水平在男性放置在围栏与女性在产卵床高于男性围栏没有女性。在男性竞争的女性，量的鱼精和血浆浓度的GtH在那些男性是成功地获得筑巢女性。一个显着的减少，精液和血浆激素烧灼后的嗅觉鼻孔表明，嗅觉刺激发挥了作用，在介导内分泌和精子的反应筑巢女性。Anosmic男性不太积极和持久的求爱，这表明，无论是女性信息素和/或高水平的激素是必要的，以保持完整的生殖行为在男性kokanee。社会引起的激素变化在调节生殖行为的作用进行了讨论。
This study examines the relationship between social status, behavioral activity, and hormone levels through the spawning cycle in male kokanee salmon (Oncorhynchus nerka). Shortly after arrival at the spawning grounds, male kokanee undergo dramatic changes in morphological and physiological condition: there is an increase in body depth, a bright silvery appearance is replaced by an intense red coloration, and spermiation commences. Males become associated with nesting females which they defend against other males. The androgens, testosterone and 11-ketotestosterone, decline slowly over the spawning period from high levels observed in the silvery males; gonadotropin (GtH II) and 17 alpha, 20 beta-dihydroxy-4-pregnen-3-one increase as males approach final maturation. Androgen and GtH levels in males placed in pens with females over the spawning bed were higher than those in males penned without females. Among males competing for females, amounts of milt and plasma concentrations of GtH were higher in those males that were successful in gaining access to nesting females. A marked reduction in milt and plasma hormones following cauterization of the olfactory nares indicates that olfactory stimuli play a role in mediating endocrine and spermiation responses to the nesting females. Anosmic males were less vigorous and persistent in their courtship, suggesting that, either a female pheromone and/or high levels of hormone are necessary to maintain full reproductive behavior in male kokanee. The role of socially induced hormone changes in modulating reproductive behavior is discussed.