Collaborative Research: A Comparison of the Mating System and Evolutionary Potential of Lemon Sharks, Negaprion Brevirostris (Poey), at Two Nursery Sites in the Western Atlantic

全球最紧迫的保护问题之一是大型捕食性鱼类，特别是鲨鱼，从海洋生态系统中消失。尽管需要采取紧急行动，但对鲨鱼种群的空间尺度、进化动态和繁殖生物学知之甚少，这对于制定有效的管理战略是必要的。这项研究将扩展对柠檬鲨繁殖生物学的长期分析，并首次使用数量遗传学方法研究大型海洋脊椎动物的关键健康特征(生长、早期存活、条件因素)的进化动态。研究人员将以之前的研究为基础，(1)直接确定雌性柠檬鲨是否会返回其出生的托儿所分娩(出生时的亲子繁殖)，(2)在两个单独的托儿所(巴哈马的比米尼和佛罗里达州的Marquas Key)检查当地和地区的柠檬鲨的交配系统，(3)使用数量遗传学来了解这两个地点健康特征的遗传性和局部适应性，以及(4)在我们位于巴哈马的主要研究地点记录人为干扰的遗传影响。由于先前的支持，必要的微卫星标记得到了充分的发展，在十年的时间里，从这两个种群中采集了2000多条鲨鱼。更广泛的影响教学和培训包括在比米尼生物实地站开设的三门大学课程，涉及正在进行的对棘鱼的研究。作为调查工作的一部分，来自世界各地的学生将在比米尼和马克萨斯基的现场以及芝加哥的实验室接受培训。代表不足的群体通过一个特别的私人资助项目成为目标，该项目每年将贫困高中生、拉丁裔、加勒比海人和非裔美国人带到比米尼生物现场站。除了在同行评议期刊上发表结果和在国际会议上发表外，我们的发现还将在即将举行的菲尔德博物馆展览“地板上的普利兹克实验室”中向公众展示。这项研究的结果将被用来为佛罗里达群岛及其周围的柠檬鲨提出适当的管理方案，并提交给巴哈马政府，以帮助将比米尼泻湖指定为海洋保护区。

One of the most pressing global conservation concerns is the loss of large predatory fish, especially sharks, from marine ecosystems. Despite the need for urgent action, very little is known about the spatial scaling, evolutionary dynamics and breeding biology of shark populations, which is necessary to develop effective management strategies. This study will expand a long-term analysis of the breeding biology of the lemon shark, and for the first time for any large marine vertebrate, examine the evolutionary dynamics of critical fitness traits (growth, early survival, condition factor) using a quantitative genetics approach. The investigators will build on previous research to (1) directly determine whether female lemon sharks return to their natal nursery for parturition (natal philopatry), (2) examine the lemon shark's mating system both locally and regionally at two separate nurseries (Bimini, Bahamas and Marquesas Key, Florida), (3) use quantitative genetics to understand heritability and local adaptation of fitness traits at these two sites, and (4) document genetic impacts of an anthropogenic disturbance at our main study site in the Bahamas. As a result of prior support, the necessary microsatellite markers are fully developed and over 2000 sharks have been sampled over ten years from these two populations. The Broader Impacts Teaching and Training include three university courses given at the Bimini Biological Field Station and involving the ongoing research on elasmobranch fishes. As part of the investigators' work, students from around the world will be trained in both the field at Bimini and Marquesas Key as well as the laboratory in Chicago. Underrepresented Groups are targeted through a special privately funded program that brings for underprivileged high school students, Latino, Caribbean and African Americans, to the Bimini Biological Field Station annually. In addition to publishing results in peer review journals and presenting at international meetings, our findings will be presented to the public in the upcoming Field Museum exhibit, "Pritzker Lab on the Floor." Results of this research will be used to suggest appropriate management schemes for lemon sharks in and around the Florida Keys and presented to the Bahamian government to assist in designating Bimini lagoon as a Marine Protected Area.