Population Structure and Phylogeography in Nassau Grouper (Epinephelus striatus), a Mass-Aggregating

To address patterns of genetic connectivity in a mass-aggregating marine fish, we analyzed genetic variation in mitochondrial DNA (mtDNA), microsatellites, and single nucleotide polymorphisms (SNPs) for Nassau grouper (Epinephelus striatus). We expected Nassau grouper to exhibit genetic differentiation among its subpopulations due to its reproductive behavior and retentive oceanographic conditions experienced across the Caribbean basin. All samples were genotyped for two mitochondrial markers and 9 microsatellite loci, and a subset of samples were genotyped for 4,234 SNPs. We found evidence of genetic differentiation in a Caribbean-wide study of this mass-aggregating marine fish using mtDNA (FST = 0.206, p,0.001), microsatellites (FST = 0.002, p = 0.004) and SNPs (FST = 0.002, p = 0.014), and identified three potential barriers to larval dispersal. Genetically isolated regions identified in our work mirror those seen for other invertebrate and fish species in the Caribbean basin. Oceanographic regimes in the Caribbean may largely explain patterns of genetic differentiation among Nassau grouper subpopulations. Regional patterns observed warrant standardization of fisheries management and conservation initiatives among countries within genetically isolated regions. Citation: Jackson AM, Semmens BX, Sadovy de Mitcheson Y, Nemeth RS, Heppell SA, et al. (2014) Population Structure and Phylogeography in Nassau Grouper (Epinephelus striatus), a Mass-Aggregating Marine Fish. PLoS ONE 9(5): e97508. doi:10.1371/journal.pone.0097508 Editor: Gen Hua Yue, Temasek Life Sciences Laboratory, Singapore Received October 26, 2013; Accepted April 18, 2014; Published May 15, 2014 Copyright: 2014 Jackson et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: Sample collection and lab work was funded by National Geographic (Young Explorers Grant #8928-11), the Reef Environmental Education Foundation (REEF), the Lenfest Ocean Program, Puerto Rico Sea Grant (#R-31-1-06), the USGS State Partnership Program (07ERAG0078), the Caribbean Coral Reef Institute of the University of Puerto Rico and grant from the Friends of Long Marine Lab. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. * E-mail: [email protected]