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

像其他翻车鱼一样，雄性南瓜籽在亲代照顾方面投入了大量资金。然而，由于卵子是在外部受精的，因此雄性采用另一种繁殖策略的机会之窗是开放的。这些“运动鞋”雄性不提供亲代照顾；相反，它们偷偷地在亲代雄性的巢穴里受精。因为亲代雄性被戴绿帽子，而且它们的亲代行为是被寄生的，所以父权如何影响亲代抚育的问题是一个非常有趣的问题。通过行为观察、实验操作和对南瓜籽太阳鱼野生种群父权的分子分析，本研究调查了运动鞋雄性的成功，并探讨了父权对该物种父权的影响。从直觉上讲，父权应该与亲代抚育有关，因为繁殖成本很高，而且在不相关的后代身上投资可能会浪费。然而，理论模型表明，在某些条件下，雄性可能会调整其亲代照顾，以应对其后代中低水平的父权，但在其他条件下则不会。大多数验证这一理论的实证工作都是在鸟类身上进行的，结果好坏参半。使用鱼类的数据和实验可能被证明对涉及实验操作的研究更易于管理。这项研究将是首次使用分子技术来调查鱼类父权和父权关怀之间的关系，并将研究被认为对这种关系至关重要的四个因素。这项研究不仅为鱼类的父权照顾和其他生殖策略提供了有价值的信息，而且还提供了一个不同的系统，可以澄清我们对父权努力和父权的理解。

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.