Fishery and conservation implications of molecular characterization and traceability of ceviche samples from Pacific Panama

Abstract

Genetic analysis of 111 samples from ceviche cocktails and fish fillets used for ceviche, obtained from fish markets and processing plants in the Pacific zone of Panama were conducted to determine species composition, trace origin (native, nonnative or imported frozen species) and CITES species status. A total of 21 species were detected (20 fishes and one invertebrate): Coryphaena hippurus (dolphin fish), Pangasianodon hypophthalmus (basa), Trachinotus falcatus (pompano), Cyclopsetta querna (toothed flounder), Atheresthes stomias (arrow-tooth flounder), Lobotes pacificus (Pacific tripletail), Bagre panamensis (Chihuil sea-catfish), B. bagre (Coco sea-catfish), Ariopsis seemanni (Tete sea-catfish), Aspistor luniscutis (yellow sea-catfish), Centropomus viridis (white snook), C. undecimalis (Union snook), Sphyrae naensis (Mexican barracuda), Oreochromis niloticus (Nile tilapia), O. mossambicus (Mozambique tilapia), Cynoscion praedatorius (Boccone weakfish), Protonibea diacanthus (blackspotted croaker), Gadus chalcogrammus (Alaska pollock), Sphyrna lewini (scalloped hammerhead shark), Makaira nigricans (blue marlin) and Dosidicus gigas (giant Humbolt squid). Native species found in ceviche samples were reduced in numbers compared with imported and cultivated ones. Thus, the most common detected fish species was basa, followed by the Nile tilapia and the dolphin fish. This is a positive result in terms of sustainability of local fisheries, since basa is imported as frozen fish meat from Asia. The same applies for Nile tilapia, a cultivated freshwater species not captured from local fisheries. For the dolphin fish, despite being common and exploited in Pacific waters, previous studies suggest its fishery is sustainable in Panama waters. In terms of conservation status, one species cataloged by IUCN as vulnerable (VU), the blue marlin (M. nigricans) and one as critically endangered (CR), the scalloped hammerhead shark (S. lewini) were detected. Sphyrae lewini is also catalog as CITES appendix II. The giant Humbolt squid (D. gigas), classified by IUCN as data deficient (DD), was the only invertebrate detected in samples obtained from a ceviche processing plant. Two sets of primers and dual labeled probes were designed for qPCR eDNA detection of the only CITES species, S. lewini. These represent the first qPCR markers for eDNA detection of S. lewini. Results from this project promote the sustainable use of fishery resources and might provide ceviche producers with a certificate from MarViva Foundation certifying that their ceviche is free of sharks or species threatened/protected by law, giving added value to their product. Molecular detection and molecular traceability are sensitive and species specific, what makes of this tool a reliable method to combat IUU (illegal, unreported and undocumented) fishing.