The Movement and Geographic Origin of Marine Larvae: A Molecular and Genetic Approach

为了了解补充在具有高度幼虫散布的海洋物种种群动态中的作用，有必要了解幼虫的运动，它们的地理来源和控制其局部丰度的力量。跟踪幼虫运动的方法仅限于短时间尺度或封闭系统内，但由于幼虫恢复困难，它们在高度扩散系统中的应用价值有限。贻贝（Mytilus edulis）是由在亲本之间的离散接触区域杂交的兄弟物种组成的。单个贻贝幼虫可以在基因上被识别为起源于亲本种群或含有杂交种群。杂交幼虫只能来自同时包含亲本分类群或F1杂交的种群。利用这一系统，将有可能在几个地理尺度上获得关于幼虫起源的信息。需要新的技术来对个体幼虫进行基因鉴定。本研究计划将开发的方法将允许直接检测个体幼虫，所需的准备工作最少，处理速度快。一旦这些技术得到发展，就有可能确定分散或聚集的幼虫的地理来源。这项新技术一旦开发出来，将用于研究贻贝种群之间接触区域的幼虫扩散。

In order to understand the role of recruitment in the population dynamics of marine species which have high larval dispersal it is necessary to understand the movement of the larvae, their geographic origin and the forces that control their local abundance. Methods for tracking larval movements have been restricted to short time scales or within closed systems but their application to high dispersal systems has been of limited value because of the difficulties with larval recovery. The mussel Mytilus edulis consists of a complex of sibling species that hybridize in discrete areas of contact between the parental forms. Individual mussel larvae can be genetically identified as having originated from either of the parental population, or from populations that contain hybrids. Hybrid larvae can only have originated from populations that contained both parent taxa or F1 hybrids. Using this system it will be possible to obtain information on the origin of larvae at several geographic scales. New techniques are required to genetically identify individual larvae. The methods which will be developed in this research program will allow individual larvae to be assayed directly, with minimal preparation and a high rate of processing. Once the techniques have been developed it will be possible to identify the geographic origin of dispersing or recruited larvae. Once developed this new technique will be employed to study larval dispersal in regions of contact between Mytilus populations.