Assessment of Population Connectivity in Caribbean Reef Fishes Using Microsatellite Loci

这个研究项目的重点是解决激烈的争论的重要性，远距离扩散与非常本地分散的幼礁鱼。大多数珊瑚礁鱼类和无脊椎动物在相对静止的幼年和成年阶段之前有一个分散的幼虫阶段。了解幼虫扩散的空间尺度是了解种群连通性的基础。大多数较早的研究表明，广泛的分散是主导力量，因此所有的种群都有很好的联系。然而，最近的一些研究表明，海洋学的细节和幼虫的行为如何可能联合收割机有利于非常有限的传播。本研究项目旨在通过检测种群间的遗传分化来显示在什么样的空间尺度上发生扩散。除了解决这一持续存在的争议外，这项活动还将有助于海洋保护区的设计，帮助确定预定保护区内珊瑚礁鱼类的来源和汇。它也可能有助于其他养护目的，例如确定加勒比和其他地方珊瑚礁鱼类的单独管理种群，即使在没有保留区的情况下也是如此。取样点是按等级安排的，小地点（珊瑚礁）在区域（由大规模海流连接的岛屿群）内的较大区域（岛屿）内。这三个研究物种的幼虫阶段的持续时间不同，可能会分散：从长的浮游幼虫持续时间在蓝头濑鱼短的蓝色条纹咕噜。遗传分析将涉及在微卫星位点对个体进行基因分型。这些基因座已被证明可以检测鱼类种群之间的细微差异，而其他方法则无法检测到。基因型数据的分析将显示在什么样的空间尺度种群分化，礁，岛，或区域，表明幼虫扩散的规模。物种间的比较结果将表明结果的普遍性，或它们对生活史性状的依赖性。

This research project focuses on resolving the vigorous debate over the importance of long distance dispersal versus very local dispersal of larval reef fishes. Most coral reef fish and invertebrates have a dispersive larval stage preceding a relatively sedentary juvenile and adult stage. Understanding the spatial scale at which larval dispersal operates is fundamental to understanding the connectedness of populations. Most older work suggests that wide dispersal is the dominant force, so all populations are well connected. Some recent work however, shows how oceanographic details and larval behavior may combine to favor very limited dispersal. The present research project is designed to show at what spatial scale dispersal is occurring by detecting genetic differentiation among populations. In addition to resolving this ongoing controversy, this activity will aid in the design of marine reserves by helping to identify sources and sinks of reef fish species in areas slated for protection. It may also be useful for other conservation purposes, such as the definition of separate management stocks of coral reef fish in the Caribbean and elsewhere, even in the absence of reservesThrough choice of sampling sites, focal species, and genetic approach in experimental design, the likelihood of detecting population differentiation and therefore scale of dispersal has been maximized. Sampling sites have been arranged hierarchically, small sites (reefs) within larger areas (islands) within regions (groups of islands linked by large-scale currents). The three study species differ in duration of the larval stage likely to disperse: from long pelagic larval duration in bluehead wrasse to short in blue-striped grunts. Genetic analyses will involve genotyping individuals at microsatellite loci. These loci have been shown to detect subtle differentiation among fish populations where other approaches have failed. Analysis of genotype data will show at what spatial scale populations are differentiated, reef, island, or region, indicating the scale of larval dispersal. Comparison of results among species will indicate the generality of results, or their dependence of life history traits.