Unintentional selection during seed culture in the Pacific abalone, Haliotis discus hannai Ino
利用贝壳颜色标记分析皱纹盘鲍苗种繁育中的无意识选择

Selective breeding is one kind of artificial selection which is carried out intentionally. There also exists unintentional process during intentional selective breeding. The aim of this study was to determine if there existed unintentional selection on Original Shell Length (OSL, as indicated by brown shell color) during subsequent seed culture in the Pacific abalone (Haliotis discus hannai Ino). As the Pacific abalone juveniles produce brown shells during their early stage when they feed on benthic diatom right after metamorphism but their shell color changes to green when fed with artificial diets during subsequent seed culture stage, we compared the average OSL on the 3rd (the beginning shell length, BSL) and 30th (the final shell length, FSL) day after feeding with the artificial diets. In 7 out of 8 groups of Pacific abalone with identical genetic origin, the average FSL was significantly larger than average BSL. Meanwhile, the standard deviation and range of the FSL were smaller than those of the corresponding BSL in six groups. The coefficients of variation of all the eight groups of FSL were smaller than those of BSL. Obviously, more juveniles with small OSL were unintentionally lost during the seed culture stage.