Rapid identification of shark species on mislabeled seafood products in Mexican markets.

Alexis Jiménez-Pérez; Carolina Garciglia-Mercado; Sergio Flores-Ramírez; Rogelio González-Armas; Felipe Galvan-Magana; Manuel Zetina-Rejón; César Cardona-Félix

Just Accepted

This article has been peer reviewed and accepted for publication. It is in production and has not been edited, so may differ from the final published form.

Rapid identification of shark species on mislabeled seafood products in Mexican markets.

Alexis Jiménez-Pérez , Carolina Garciglia-Mercado, Sergio Flores-Ramírez, Rogelio González-Armas, Felipe Galvan-Magana, Manuel Zetina-Rejón, César Cardona-Félix

Abstract

Context: Sharks have been globally captured for decades. Sharks’ exploitation lacks proper regulation, hindering an assessment of captured and traded individuals. This necessitates a method to quickly and easily identify shark species. Aims: This study aims to standardize and validate a rapid and effective method of shark species identification from Mexican markets. Methods: In this study, LAMP assays were developed for identification of five commercially important shark species in the northwest region of Mexico: Carcharhinus falciformis, Prionace glauca, Isurus oxyrinchus, Sphyrna zygaena, and Sphyrna lewini. A total of 350 samples were collected from markets, labelled as "cazón" (small shark), "marlín" (marlin), and "tiburón" (shark). Key results: Through LAMP assays standardization, it was possible to identify individuals of these five species: 17 individuals of S. zygaena, 17 of S. lewini, 24 of C. falciformis, 26 of P. glauca, and 85 of I. oxyrinchus. To validate species identification by LAMP, sequences of COI and ITS2 were obtained and analyzed by BLASTn. It was obtained a 100% match identity for LAMP assays and their sequences. Additionally, DNA limit of detection was determined down to 0.1 ng/μL of shark DNA. Conclusions: These results underscore an urgent need to effectively identify commercially traded species, some of which may be endangered; and to establish species-level labelling on national policies. Implications: Application of correct species labels on national seafood products can suggest to consumers to be responsible and conscious, at the moment when they are choosing their food.

PC24068 Accepted 29 January 2025