Jonas da Paz Aguiar1, Paola F Fazzi-Gomes2, Igor G Hamoy2, Sidney Eb Dos Santos3, Iracilda Sampaio1. 1. Laboratory of Genetics and Molecular Biology, Institute of Coastal Studies, Federal University of Pará, Belém, Brazil. 2. Laboratory of Applied Genetics, Institute of Socio-environmental Studies and Hydrological Resources, Federal Rural University of the Amazon, Belém, Brazil. 3. Laboratory of Human and Medical Genetics, Institute of Biological Sciences, Federal University of Pará, Belém, Brazil.
Abstract
BACKGROUND: In recent years, tracing of alimentary produce of animal origin has become increasingly important, for economic, food safety and ecological reasons. The tambaqui, Colossoma macropomum, is the native fish most farmed in Brazil. The reliable identification of the origin of tambaquis (wild or farmed) offered for sale to the general public has become necessary to satisfy regulatory norms and uphold consumer confidence. Molecular methods based on the analysis of DNA sequences have often been used to evaluate the potential for tracing farmed fish, given their reliability and precision. RESULTS: Full likelihood and Bayesian approaches proved to be the most efficient for the identification, respectively, of individuals and populations for most of the fish sampled from seven hatcheries and one wild stock. The exclusion method and genetic distances were the least effective approaches for the identification of individuals and populations. The Bayesian method identified correctly more than 99% of the fry from most stocks, except those of the Santarém hatchery and River Amazon wild stock, which presented the best results for individual identification. CONCLUSIONS: The identification of populations was effective for most hatcheries, although the identification of individuals from most stocks was hampered by the reduced genetic variability.
BACKGROUND: In recent years, tracing of alimentary produce of animal origin has become increasingly important, for economic, food safety and ecological reasons. The tambaqui, Colossoma macropomum, is the native fish most farmed in Brazil. The reliable identification of the origin of tambaquis (wild or farmed) offered for sale to the general public has become necessary to satisfy regulatory norms and uphold consumer confidence. Molecular methods based on the analysis of DNA sequences have often been used to evaluate the potential for tracing farmed fish, given their reliability and precision. RESULTS: Full likelihood and Bayesian approaches proved to be the most efficient for the identification, respectively, of individuals and populations for most of the fish sampled from seven hatcheries and one wild stock. The exclusion method and genetic distances were the least effective approaches for the identification of individuals and populations. The Bayesian method identified correctly more than 99% of the fry from most stocks, except those of the Santarém hatchery and River Amazon wild stock, which presented the best results for individual identification. CONCLUSIONS: The identification of populations was effective for most hatcheries, although the identification of individuals from most stocks was hampered by the reduced genetic variability.