Species and hybrid identification of sturgeon caviar: a new molecular approach to detect illegal trade

Abstract

Overexploitation of wild populations due to the high economic value of caviar has driven sturgeons to near extinction. The high prices commanded by caviar on world markets have made it a magnet for illegal and fraudulent caviar trade, often involving low-value farmed caviar being sold as top-quality caviar. We present a new molecular approach for the identification of pure sturgeon species and hybrids that are among the most commercialized species in Europe and North America. Our test is based on the discovery of species-specific single nucleotide polymorphisms (SNPs) in the ribosomal protein S7, supplemented with the Vimentin gene and the mitochondrial D-loop. Test validations performed in 702 specimens of target and nontarget sturgeon species demonstrated a 100% identification success for Acipenser naccarii, A. fulvescens, A. stellatus, A. sinensis and A. transmontanus. In addition to species identification, our approach allows the identification of Bester and AL hybrids, two of the most economically important hybrids in the world, with 80% and 100% success, respectively. Moreover, the approach has the potential to identify many other existing sturgeon hybrids. The development of a standardized sturgeon identification tool will directly benefit trade law enforcement, providing the tools to monitor and regulate the legal trade of caviar and protect sturgeon stocks from illicit producers and traders, hence contributing to safeguarding this group of heavily threatened species.

Nuclear DNA markers for identification of Beluga and Sterlet sturgeons and their interspecific Bester hybrid

“…ruthenus and A . baerii from other sturgeon species with efficacy of 96% and 60.6%, respectively 9 . However, it did not discriminate between these two species, and there was no nucleotide variability in that intron allowing discrimination of H .…”

“…However, it did not discriminate between these two species, and there was no nucleotide variability in that intron allowing discrimination of H . huso 9 . Recently, Boscari, et al .…”

“…However, mtDNA has limitations for identification of hybrids due to maternal inheritance, and RAPD and AFLP have low reproducibility and are costly and time consuming. Five species of sturgeon, Acipenser naccarii , Acipenser fulvescens , Acipenser stellatus , Acipenser sinensis , and Acipenser transmontanus and their hybrids can be unambiguously identified by nuclear DNA markers 9 . Recently, Boscari, et al .…”

Blue Economy and Biodiversity Surveillance: Fish Caviar Substitute Rapid Discrimination

“…The expanding criminal caviar trade is a serious threat to the survival of wild sturgeon populations, diminishes the effectiveness of management and conservation programs, undermines legal trade and threatens the sustainable production of caviar [14,23].…”

“…In our study the two theoretical enzymes, HpaII and MboII, allowed a correct discrimination between the sturgeon species, Cyclopterus lumpus, Mallotus villosus, Trisopterus minutus minutus and Acipenser baerii and our experiments show that the discrimination is suitable with only one step too, using the restriction enzyme MboII. Taking into consideration the great commercial value of these species as caviar or caviar substitutes, this method showed a rapid way for exposing commercial frauds, like mislabeling of caviar lots, to avoid commercial frauds on the fish market [23,30].…”