The Evolution of Polyandry in the Horseshoe Crab, Limulus Polyphemus

PI：H.Jane Brockmann Proposal No：06411750标题：多夫多妻制在马蹄蟹中的进化长期以来，生物学上一直认为，雄性可以通过多个伴侣来提高他们的生殖成功，而雌性则不能。然而，许多物种的雌性会交配繁殖。有许多解释，包括女性没有受益的可能性(一夫多妻制是男性竞争的结果)；或者，女性要么受益于男性提供的资源，要么受益于配偶质量的提高或更大的遗传兼容性。这项研究在马蹄蟹身上评估了这些假设，马蹄蟹是一种雄性只提供父亲身份的物种。马蹄蟹成双成对地产卵，一些雌性会吸引更多的卫星雄性，这些雄性可能会让许多卵受精。这项研究测量了在野外和实验室中繁殖和单次交配的雌性是否成功。实验考察了多重亲子关系对雌性产卵成功率、卵发育和幼虫存活率和活力的影响。作为一种古老的独立进化的节肢动物，马蹄蟹为我们提供了一个独特的机会来扩大我们对生殖行为进化的理解。这个项目有更广泛的影响。首先，作为诱饵和用于生物医药行业的马蹄蟹的收获是有管理的，因为马蹄蟹卵是滨鸟的重要食物。这项研究提供了用于管理这一有争议物种的关键数据。其次，马蹄蟹是一门成功的课程的核心，该课程向初中生传授科学、管理和保护方面的知识，PI和她的学生参与了这一努力。第三，这项研究的结果被传播到一个关于马蹄蟹生物学和保护的公共网站和国际论坛。最后，该项目为各级学生提供了许多机会，学习如何在野外和实验室环境中对迷人的海洋无脊椎动物的行为进行研究。

PI: H. Jane BrockmannProposal No.: 06411750Title: The Evolution of Polyandry in the Horseshoe Crab, Limulus polyphemus It is a long-held view in biology that males can enhance their reproductive success through multiple partners whereas females cannot. Yet, females of many species mate multiply. Many explanations exist including the possibility that females do not benefit (polyandry results from male competition); or, alternatively, that females benefit either from resources that males provide or through improved mate quality or greater genetic compatibility. This study evaluates these hypotheses in the horseshoe crab, a species in which males provide only paternity. Horseshoe crabs spawn in pairs with some females attracting additional satellite males that may fertilize many eggs. This study measures the success of multiply and singly mated females in both the field and laboratory. Experiments examine the effect of multiple paternity on female egg-laying success, egg development and larval survivorship and viability. As an ancient and independently evolved arthropod, horseshoe crabs offer a unique opportunity to extend our understanding of the evolution of reproductive behavior. This project has many broader impacts. First, the harvest of horseshoe crabs as bait and for use in the biomedical industry is managed because horseshoe crab eggs are an important food for shorebirds. This study provides crucial data that are being used in the management of this controversial species. Second, horseshoe crabs are at the center of a successful curriculum to teach middle and high school students about science, management and conservation and the PI and her students participate in this effort. Third, the results of this study are disseminated to a public web site and international forum on the biology and conservation of horseshoe crabs. Finally, the project provides many opportunities for students at all levels to learn how to conduct research in field and laboratory settings on the behavior of a fascinating marine invertebrate.