DNA-based methods for species authentication of Amazonian commercial fish

Amazonian fish represent a food market in expansion. In the present work, three genetic methods were developed for species identification of Amazonian marketed fish. These methods were based on: polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), forensically informative nucleotide sequencing (FINS) technique, and PCR-fragment size visualization of 5S rDNA in agarose gels. They enabled the identification of 20 species belonging to nine taxonomic families and could be applied for fish food authentication and commercial labeling of Amazonian fisheries and aquaculture products. Employing these methods we achieved successful identification of commercial samples obtained from restaurants, either salted or frozen, thus confirming the utility of these methods for routine control of Amazonian fish food. The methods were compared in terms of time, equipment requirement and cost, and we concluded that they could be of utility for application in real life food quality control in developing countries.