DISSERTATION RESEARCH: Costs of Parental Behavior, and Patterns of Paternal Effort and Paternity in the Pumpkinseed Sunfish (Lepomis gibbosus)

与其他太阳鱼一样，雄性南瓜籽在父母照料方面投入了大量资金。然而，因为卵子是在外部受精的，所以一扇机会之窗为采用替代生殖策略的雄性打开了。这些“运动鞋”雄性并不提供父母的照顾；相反，它们会偷偷地将受精放在父母的巢中。因为父母的雄性是戴绿帽子的，他们的父母行为是寄生的，亲子关系如何影响父母照顾的问题是很有意义的。通过行为观察、实验操作和对野生南瓜籽太阳鱼亲子关系的分子分析，这项研究调查了运动鞋雄性太阳鱼的成功，并探索了这种物种中父亲照顾的影响。从直觉上讲，父爱应该与父母的照顾有关，因为繁殖是昂贵的，在无关后代上的投资可能会被浪费。然而，理论模型表明，在某些情况下，雄性可能会调整其父母的照顾，以应对其幼崽中的低水平父子关系，但在其他情况下则不会。测试这一理论的大部分实证工作都是在鸟类身上进行的，并产生了好坏参半的结果。使用FISH的数据和实验可能被证明对涉及实验操作的研究更容易管理。这项研究将是第一次使用分子技术来研究鱼类的父子关系和父亲照顾之间的关系，还将检查被认为对这种关系至关重要的四个因素。这项研究不仅有望为鱼类的父性照料和替代繁殖策略提供有价值的信息，而且还将提供一个不同的系统，以澄清我们对父性努力和父权关系的理解。

Like other sunfish, male pumpkinseeds invest substantially in parental care. However, because eggs are fertilized externally, a window of opportunity is open for males adopting an alternative reproductive tactic. These "sneaker" males do not provide parental care; instead they sneak fertilizations in the nest of parental males. Because parental males are cuckolded and their parental behavior is parasitized, the question of how paternity affects parental care is of substantial interest. Using behavioral observations, experimental manipulations, and molecular analyses of paternity in a wild population of pumpkinseed sunfish, this study investigates the success of sneaker males and explores how paternal care is affected by paternity in this species.Intuitively, paternity should be related to parental care, since reproduction is costly and investment in unrelated offspring may be wasted. However, theoretical models suggest that males may adjust their parental care in response to low levels of paternity within their brood under certain conditions but not others. Most of the empirical work testing this theory has been conducted with birds and has produced mixed results. Data and experiments using fish may prove more manageable to studies involving experimental manipulation. This study will be among the first to use molecular techniques to investigate the relationship between paternity and paternal care in a fish, and will also examine the four factors thought to be critical to such a relationship. This study is expected to provide not only valuable information regarding paternal care and alternative reproductive strategies in fishes, but also a different system that may clarify our understanding of paternal effort and paternity.