Abstract:

Aims: Sturgeons are important economic fishes with high market value. However, with the overfishing and the habitat destruction, the natural population of sturgeon have been declined worldwide. To address the challenges, all sturgeon species has been included in the appendices of CITES in 1997, besides, all species in natural waters of China are also included in the China’s protection catalogue under the Wildlife Protection Law. The identification of sturgeons still faces some difficulties. There are many identification methods for sturgeons, but most of them are applicable conditionally within range of species, respectively. This study aims to integrate available methods to meet more identification requirement in judicial authentication, wildlife supervision and germplasm resource management.
Methods: This study analyzed the identification methods and search the trade situation of sturgeons from the CITES database. Based on this, an integrated identification method which include mtDNA genetic analysis, Single Nucleotide Polymorphism (SNP) analysis and microsatellite DNA was established and analyzed to evaluate the effectiveness in identifying the 11 kinds of commercial sturgeon species and their hybrids.
Results: A total of 36 kinds of aquaculture sturgeons can be found from the CITES sturgeon trade database, including 14 hybrids and 22 purebred species. Although there are many methods to identify sturgeon species, molecular biological methods are proved to be effective identification methods. By integrating three identification methods above, blind detection is applicable to identify 11 purebred sturgeons and their hybrid sturgeons referring to the current international trade. Among them, two kinds of hybrid sturgeons can be accurately identified: (1) The hybrid sturgeons with parents from Acipenser ruthenus, Huso dauricus, A. schrenckii, Huso huso, A. stellatus or A. transmontanus. (2) The hybrid sturgeons whose female parent is A. ruthenus and male parent is A. naccarii or A. fulvescens or A. sinensis. Besides, the purebred H. dauricus, A. transmontanus, A. fulvescens and A. sinensis can be identified only under the current trade background. However, the hybrid sturgeons with parents from A. baerii or A. gueldenstaedti still cannot be accurately identified. Meanwhile, it is difficult to distinguish some purebred sturgeons among several of their hybrid sturgeons (A. baerii or A. gueldenstaedti as male parent).
Conclusion & suggestion: The identifiable sturgeon species are still limited based on the literature, the integration of the method above could satisfy the needs of sturgeon identification in some scenarios and is important for sturgeon conservation, trade product detection and germplasm resources management. Since many species still lack available markers for identification, developing new specific markers and further verifying the scope of existing specific markers should be encouraged with the international cooperation for the diverse sturgeon materials, especially for A. baerii and A. gueldenstaedti as parents of many hybrid sturgeons.

Key words: sturgeon, species identification, SNP, mtDNA, microsatellite DNA, sturgeon conservation, germplasm resources management