Abstract: China has recently become the leader country for sturgeon aquaculture and caviar production, deeply changing the traditional geography of this market in few years. As a consequence, some species originating from the Far East Asia increased their economic relevance, joining the ones traditionally harvested for caviar. In this context, the possibility to reliably and promptly identify these species on the market has increasing importance for the enforcement of control actions against illegal trade or commercial frauds. The present study focuses on two commercially relevant species, massively reared in China not only as pure species but also as reciprocal hybrids: the Amur (Acipenser schrenckii) and Kaluga (Huso dauricus) sturgeons. We assess the identification power of two putatively diagnostic markers isolated from two predicted introns of the nuclear coding gene Ribosomal Protein L8. The markers were tested on tissue or caviar of 508 individuals of the two species and 31 hybrids. In order to compare results across loci, most individuals were also checked at two already published microsatellite markers, with a good, even if incomplete, identification efficiency for the two species. No marker showed fixed alternative alleles between Amur and Kaluga sturgeons, confirming the difficulty of distinguishing these two sympatric species in spite of the marked morphological differences and the consequent classification into different
genera. So far, the multi-locus panel here used represents the more effective tool for the genetic identification of pure Amur and Kaluga sturgeons and resulted to be fully efficient to validate caviar and tissues obtained from hybrids between the two species.
Elisa Boscari, Anna Barmintseva, Shuhuan Zhang, Huamei Yue, Chuangju Li, Sergei V. Shedko, Dietmar Lieckfeldt, Arne Ludwig, Qiwei W. Wei, Nikolai S. Mugue, Leonardo Congiu*. Genetic identification of the caviar-producing Amur and Kaluga sturgeons revealed a high level of concealed hybridization. Food Control, 2017, 82: 243-250.
