DNA Barcoding, Identification and Validation of the puffer fish (Order:
Tetraodontiformes) in China Coastal Waters
Abstract
Tetraodontiformes is a special group of higher teleosts, with a long and
problematic taxonomic history due to their wide distribution and species
diversity. It is a difficult task for both professionals and
nonprofessionals to accurately identify all species only according to
morphological characteristics. DNA barcoding can identify species at the
molecular level. In this study, we collected 616 specimens of
Tetraodontiformes and their DNA barcodes from the coastal waters of
China. According to the morphological characteristics, 50 species were
preliminarily identified, belonging to 23 genera, 6. Among them, DNA
barcoding analysis showed that Takifugu pseudommus and Takifugu
chinensis are the synonyms of Takifugu rubripes. And Lagocephalus
wheeleri is the synonym of Lagocephalus Spadiceus. The third important
finding is that the species of Takifugu have close genetic relationship.
If T. rubripes, T. pseudommus and T. chinensis are taken as one species,
the average interspecific genetic distance of Takifugu is 6.21 times of
the average intraspecific genetic distance, which does not reach the DNA
barcode threshold of more than 10 times proposed by Hebert. Among them,
the genetic distance between T. oblongus and T. stictonotus is the
largest, 0.045; And between T. bimaculatus and T. flavidus is the
smallest, only 0.013. However, species can be clustered into separate
clades in the NJ tree. In conclusion, this study provided molecular
basis for solving the problem of confusion in the classification of
Tetraodontiformes, it found that there are synonym phenomena in the
order, and provided molecular evidence for clarifying the valid species
names of Lagocephalus Spadiceus and Takifugu rubripes. The results can
provide reliable DNA barcoding information for the identification and
classification of Tetraodontiformes, and also provide technical support
for the development and utilization of puffer fish resources and the
identification of the original components of related commodities on the
aquatic product market.