Regional Differences In Otolith Morphology Of The Sea Bass

Fish otoliths have been used to identify species a long time ago. Recent decade, some foreign scholars developed morphological characteristics of otolith to population identification because fish otolith has many research advantages. These advantages include the otolith shape of adult fish has population specialties, the growth of fish otolih is regular to seasons, the fish otoliths are not easy to be damage , the growth of fish otolith is steadier than fish squama and so on. For these research advantages, fish otoliths are regarded by more and more researchers and morphological characteristics of otolith has became one of the most important methods of population identification.Sea bass is belonged to Perciformes, Serranidae and Lateolabrax. Sea bass has high flexibility to salinity and temperature. Sea bass distribute along the shore of Japan, Korea and China. Sea bass grow rapidly and. The growth of sea bass is rapidly and low-disease. Sea bass has big body size and the meat of sea bass is delicious. So sea bass has been breed widely in China.Japanese Lateolabrax japonicus and Chinese L. maculates were identified as one species before. With the develop of research method, Japanese researchers begin to realize to there are three species in Lateolabrax. Many this kind of studies has been done, but none of them are research from morphology of otolith.Morphology of otolith of sea bass was applied to identify Japanese L. japonicus and Chinese L. maculates in this paper. The otoliths of them were collected in Tokyo Bay (Japan) and Chinese marine regions including Zhoushan Islands, Fuzhou and Xiamen offshore, and Beibu (Tonkin) Gulf of Guangxi Province and cluster-analyzed with difference coefficient, Mdiff, and so on. Significant differences in relation of otolith weight and otolith length and relation of otolith weight and body length were found between L. japonicus and L. maculates. The Euclidean distances of them varied between 4.538 and 5.656, while those of the L. maculates samples were between 2.108 and 4.566. Therefore, significant geographical differentiation in otolith morphology has been took place in different Chinese coastal waters. Three geographical populations of L. maculates in China are proposed, i.e. Zhonshan, Fuzhou-Xiamen, and Guangxi populations.Population research is one of the most important works in fishery research, which would provide theoretical base on resources conservation and its sustainable utilization. Otolith shape was population specific for Lateolabrax maculates from this research.