The Application Of Fish DNA Baroding In Species Identifcation Of Fish Larvae And Eggs In Zhejiang Coast

The fishery resources in Zhejiang Coastal Sea are abundant.The waters provide impotant spawning sites and habitats for a variety of marine economic fish species.It is generally recognized that fish eggs and larvae are important fishery complementary resources.The composition and quantity of species and the quality of coastal ecological environment directly affect the amount of fish resources.This study aimed to establish DNA barcode technology for identification of fish eggs and larvae,to understand the composition of species in spawning areas along Zhejiang Coastal waters,to provide baseline information for fisheries management.The main results are summarized as follows:1.Adult samples were collected from coastal areas of Zhoushan Islands,including Dengbu,Taohua,Liuheng,Xiazhi,Zhujiajian,Daishan,Dachangtu,Xiaochangtu,Qushan,Sijiao,and Gouqi and Cangnan.The collection was conducted from the 2011 summer to 2014 summer.Fishing method for offshore fishing vessels and offshore fixed nets.A total of 71 marine fishes were identified,belonging to 8 orders and 25 families.There are 3 kinds of similarity: that between 92%-98% can be identified to the level of genus There are 3 kinds of similarity less than 92%.The similarity of the remaining 3 species was less than 92%.2.Samples of fish eggs and larvae were collected during May 2014-November 2015 using rental boats and plankton NETs(length 280 cm,internal diameter 80 cm,opening area 0.5m2,mesh size 0.5mm,trawl speed 2 nmi /h in the sea,trawling time 10 min).With morphology,16.9% of the samples were identified to the family level,and 1.4% were identified to the species level.DNA barcoding results showed that 21 fish species were identified out of 73 samples,belonging to 9 families;67 samples shared more than 98% of similarity with their respective reference species in GenBank database,accounting for 91.8% of the samples identifiable to the species level.The remaining 6 samples shared 83% to 92% of similarity with their respective refrence species.DNA barcoding technology is a powerful complement to confirm the results of morphological results.DNA barcoding is an accurate,standardized,and efficient tool for species identification,and possesses a broad prospect of application in fish biodiversity research.3.The average value of pairwise K-2-P distance is 0.56% within species,9.19% between species within genus,21.72% between genus within families,and 25.25% between families within orders,which indicated that the K-2-P distance within species is far smaller than that between species.Overall,the COI gene phylogenetic tree of fish eggs and larvae is in accordance with morphological classification of the fishes.Our results demonstrated that the DNA barcoding technology can be applied to the species identification of fish eggs and larvae.