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

为了了解补充在幼虫高度分散的海洋物种种群动态中的作用，有必要了解幼虫的运动、它们的地理来源以及控制它们当地丰度的力量。跟踪幼虫移动的方法被限制在短时间尺度上或在封闭系统内，但由于幼虫回收困难，它们在高分散系统中的应用价值有限。紫贻贝是由亲缘种组成的复合体，它们在亲本之间的离散接触区域杂交。个别贻贝幼体可以从遗传上被鉴定为起源于亲本种群，或者来自包含杂交种的种群。杂交幼虫只能来自同时含有亲本类群或F1杂交种的种群。利用这一系统，将有可能在几个地理尺度上获得有关幼虫来源的信息。需要新的技术来从基因上识别单个幼虫。在这项研究计划中开发的方法将允许直接检测单个幼虫，只需最少的准备和较高的处理速度。一旦开发出这些技术，就有可能确定散布或招募幼虫的地理来源。一旦开发出来，这项新技术将被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.