小黄鱼鱼卵的形态学及遗传学鉴别

Morphological and Genetic Identification of Larimichthys polyactis Eggs

为验证小黄鱼鱼卵形态学鉴别的准确性，以及COI基因序列在小黄鱼鱼卵鉴别中应用的可行性，对黄海中南部近岸海域15个站位采集的两组平行样品分别进行传统形态学鉴别和COI基因片段序列的测定。形态学鉴别结果显示，7站出现小黄鱼鱼卵，共计128粒。卵径1．242-1．535mm，油球径0．414-0．567mm。遗传学鉴别结果显示，共108个个体成功扩增并测序，共检测到17个单倍型，与小黄鱼间的遗传距离在0．000-0．038之间；与其他石首鱼科鱼类序列的遗传距离在0．112～0．317之间。Kimura双参数模型构建的NJ系统树聚类结果显示，鱼卵与小黄鱼单倍型聚为一支，与其他石首鱼科鱼类序列分为不同的分支，推断108粒鱼卵均为小黄鱼。对比形态学和遗传学鉴别结果，不存在显著差异（P=0．844〉0．05）。结果表明，小黄鱼鱼卵的形态学鉴别具有较高的准确性，线粒体COI基因可应用于小黄鱼鱼卵的鉴别。

In order to verify the correctness of morphological identification and identify if the partial se：- quences of mitochondrial CO I gene can be a useful tool to identify Larimichthys polyactis eggs, the eggs which were collected at 15 stations in the central and southern Yellow sea were identified by morphological and ge- netic method respectively. The results of morphological identification showed that 128 L. polyactis eggs were found at 7 stations, and the diameter ranges of eggs and oil droplets were 1.242-1.535 mm and 0.414-0.567 mm respectively. The genetic identification results showed that there were 108 sequences which were identified yielding 17 haplotypes. The Kimura 2-parameter distance between fish eggs and L. polyactis was 0.000-0.038; but the distance between eggs and the other species of Sciaenidae was 0.112-0.317. The neighbor-joining （NJ） tree indicated that haplotypes of eggs and L. polyactis were assembled at the same embranchment, but the eggs were assembled at different embranchments with the other Sciaenidae spp. Therefore, the 108 fish eggs were i- dentified as L. polyactis. According to the non-parametric test, there is no significant difference between the results of morphological and genetic identification （P=0.844〉0.05）. The findings of this study clarified that the traditional identification of L. polyactis eggs is relatively accurate, and mitochondrial CO I gene can he used to identify L. polyactis eggs.