DISSERTATION RESEARCH: Investigating patterns and processes of evolution, ecology, and diversification in carangiform fishes

该项目研究了两种标志性海洋鱼类的遗传多样性，即巨型Trevally和蓝鳍Trevally。这两个物种是整个印度洋和太平洋珊瑚礁和岩礁的顶级捕食者，对手工，商业和体育渔业具有很高的价值。该研究将调查遗传多样性与环境变量之间的相关性（例如，在印度洋-太平洋地区，研究人员利用海洋温度和洋流来确定可能导致这些鱼类在不同地理位置的基因组中观察到差异的物理障碍。该项目的重点是西印度洋，该地区缺乏足够的海洋保护措施，主要是因为缺乏必要的数据，使政府能够做出管理决策。由于缺乏关于这两种Trevally的数据，再加上它们的经济重要性，该项目具有直接的社会影响。研究人员将与政府和非营利合作者分享数据，并为研究生提供强有力的科学培训，以及与美国，南非和塞舌尔的公众进行接触。 为了实现项目目标，研究人员将首先使用下一代测序技术进行海景遗传分析，特别是针对单核苷酸多态性（SNP）的双消化限制性位点相关DNA测序（RADseq），以检查C. A. bilis和C.黑臀目个体的分布范围。将使用生物物理耦合模型分析海景特性，该模型将海洋学数据与这些物种的生物属性相结合。将建立各种模型，最大限度地提供与遗传数据互补的空间尺度海洋学信息。第二个组成部分包括一个生态地理分析，重点是通过使用古气候数据来表征可能推动进化并影响这两个物种的历史和现在数据分布的物理和生物力量，从而表征历史基因流的模式。这种方法使用高分辨率的古海洋学模型，再加上当代基于GIS的物种分布建模算法，以生成每个物种的paleodistribution适合值。这些paleodistribution作为替代假设，以测试对SNP数据集。这些分析结合起来，将提供对塑造这两个重要渔业物种的多样化和连通性的当代和历史过程的见解。

This project examines genetic diversity in two species of iconic marine fishes, the Giant Trevally and the Bluefin Trevally. Both species are top predators on coral and rocky reefs throughout the Indian and Pacific Oceans and are highly valued for artisanal, commercial, and sport fisheries. The research will investigate the correlation between genetic diversity and environmental variables (e.g., ocean temperature and currents) in the Indo-Pacific to identify physical barriers that might lead to observed differences in the genomes of these fishes in different geographic locations. The project focuses on the western Indian Ocean, a region lacking sufficient marine conservation measures in large part due to a scarcity of data necessary to inform governments making management decisions. Given the lack of data on these two species of Trevally, coupled with their economic importance, this project has direct societal implications. The researchers will share data with governmental and non-profit collaborators and incorporate strong scientific training components for graduate students, as well as engagement with members of the public in the USA, South Africa, and Seychelles. To accomplish the project objectives, the researchers will first conduct seascape genetic analyses using next generation sequencing techniques, specifically double digest restriction site associated DNA sequencing (RADseq) targeting single nucleotide polymorphisms (SNPs) to examine fine-scale genetic structure within and among C. ignobilis and C. melampygus individuals across their range. Seascape properties will be analyzed using coupled biological-physical models that integrate oceanographic data with biological attributes of these species. Models will be generated that maximize the availability of oceanographic information at a spatial scale complementary to the genetic data. The second component includes a phylogeographic analysis focused on characterizing patterns of historic gene flow by using paleoclimatic data to characterize physical and biological forces that may have driven evolution and influenced historical and present data distributions of the two species. This methodology uses high-resolution paleoceanographic models coupled with contemporary GIS-based species distribution modeling algorithms to generate paleodistribution suitability values for each species. These paleodistributions serve as alternate hypotheses to test against the SNP dataset. In combination, these analyses will provide insight on contemporary and historical processes shaping the diversification and connectivity of these two important fishery species.