中文摘要：

分析了中国近海丹东、营口、舟山、温州和福州32尾小黄鱼线粒体Cytb基因的862bp序列，共检测到31个变异位点，13个简约信息位点，26个单倍型；单倍型多样性为0．984＋0．013，核苷酸多样性为0．00395。高单倍型多样性和低核苷酸多样性，Tajima’s中性检验为负值且显著，核苷酸不配对分析呈单峰曲线，在简约性网络图中单倍型呈星状分布，表明小黄鱼经历过种群扩张。扩张年代约为0．14MY前。群体间较低的Fst值和较高的Nm值，在NJ系统树和简约性网络图中不同地理来源的单倍型交错分布．分子方差分析都表明群体间未出现明显的遗传分化，与传统的地理群体划分并不一致。推测小黄鱼产浮性卵、生活史中出现大规模的洄游以及扩张后的群体尚未在迁移与漂变间达到平衡可能是未检测到显著地理和谱系结构的主要原因。

英文摘要：

862 bp mtDNA cytochrome b gene of 32 individuals of Larimichthys polyactis collected in Dandong, Yingko, Zhoushan, Wenzhou and Fuzhou along coastal waters of China were determined. 26 haplotypes were defined by 31 variable sites and 13 parsimony-informative sites. The global haplotype diversity （h） and nucleotide diversity （π） were 0.984±0.013 and 0.00395 respectively, indicating high haplotype diversity and low nucleotide diversity in Larimichthys polyactis.The neutral test of Tajima＇s, mismatch distribution and star-like statistical parsimony cladogram revealed a population expansion at about 0.14 Mya. Low genetic differentiated index （Fst） and high gene flow（Nm）,intertwined haplotypes of various geographic populations in NJ tree and TCS, and analysis of molecular variance （AMOVA） among populations showed no significant population structure, which were inconsistent with conventional partitions of geographical population Long-term migration, pelagic eggs and insufficient time to attain a equilibrium after a large range population expansion, may be attributed to account for the lack of genetic structure.