| Summary: | 碩士 === 國立臺灣海洋大學 === 海洋生物研究所 === 100 === Total of 12,161 fish larvae were towed by using 1000 μm Round Mouth Ichthyplanlton net (RMI) from bottom to surface at 25 stations in the East China Sea in July, 2009 (criuse OR1_905). All fish larvae were classified to 219 morpho-types by morphological characters. The use of traditional morphological identification method could be identified to 12 order 59 family. by using DNA barcoding, 38 types can be identified to family, 25 to genus, 72 to species level, a total of 135 taxa, which belonging to 14 order, 61 families, 91 genus and 72 species. The identificaton rate is much better than morphological characters. The total average abundance of 1044±1720 ind./103m3 . The dominant species of fish larvae in ECS were Engraulis japonicus(25.96%), followed by Auxis rochei, Bostrychus sp., Atrobucca nibe, Benthosema sp., Pennahia argentata, Decapterus macarellus, Valenciennea wardii , Trichiurus japonicus, Auxis thazard, Harpadon nehereus, Apogon lineatus , Cynoglossus interruptus etc. These 13 species provide 70.40% of the total abundance of fish larvae. Result of cluster analysis distinguished four station groups (A - D). The major contribution species of A group (offshore group) were Auxis rochei, Trichiurus japonicus and Auxis thazard, B group (inshore group) were Engraulis japonicus, Bostrychus sp. and Atrobucca nibe , C group (sK) was Engraulidae gen. sp.3 and Engraulis japonica, and D group (upper Yangtze river estuary group) were Harpadon nehereus and Engraulis japonica. Result of correlation coefficients showed that total abundance of fish larvae was positively correlated to chlorophyll a concentration but negatively correlated to temperature and salinity. The species number and diversity were negatively correlated to chlorophyll a concentration but showed a close positive relationship with temperature and salinity. It suggest that species diversity was double impact by the temperature and salinity.
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