有效群体大小对蛤仔F_1生长和存活影响

Effects of effective population size on the F_1 growth and survival of the Manila clam Ruditapes philippinarum

对不同有效群体大小(Ne=2、4、8、16、32、200)的蛤仔F1代生长和存活性状进行了比较。结果表明:浮游期,各试验组幼虫壳长均未表现出显著性差异(P>0.05),实验组Ne=200的存活率低于其他各实验组,并随着日龄的增长,差异越来越显著;稚贝期,各实验组的壳长和存活率的变化规律和浮游期基本一致。对壳长变异情况分析表明,浮游期,随着群体有效含量的增大,子代开始出现小型个体和大型个体,壳长分布变异逐渐明显;稚贝期,各试验组组内壳长变异进一步加剧,除Ne=2试验组稚贝壳长介于400μm和600μm之间外,其他各试验组均出现明显的小型和大型个体,表现为有效群体越大,组内稚贝壳长变异越为明显。

In this study, the growth and survival were compared among different effective population sizes （Ne=2, 4, 8, 16, 32, and 200） of the F1 generation of the Manila clam Ruditape philippinarum. The results showed that the difference was not significant in shell length （P〉0.05） at larval stage, although the survival of experimental group （Ne=200） was lower than other experimental groups. Moreover, the difference was significant with increasing age. At the juvenile stage, the tendency of growth and survival was the same as that at the larval stage. The results of the variation in shell length showed that the offspring developed into maximization and miniaturization, and the distri-bution of the shell length was significant. The shell length of experimental group （Ne=2） ranged from 400 to 600μm, however, the other groups exhibited maximization and miniaturization individuals. The results also showed that the larger the effective population size was, the more the variation of the shell length was.