Fish and seafood traceability based on AFLP markers: Elaboration of a species database Milena Maldini a , Francesco Nonnis Marzano a, ⁎ , Gloria González Fortes a,b , Riccardo Papa a , Gilberto Gandolfi a a Dipartimento di Biologia Evolutiva e Funzionale, University of Parma, Parco Area delle Scienze 11/A, 43100 Parma, Italy b Departamento de Genética, University of Santiago de Compostela, Campus de Lugo, 27002 Lugo, Spain Received 8 March 2006; received in revised form 10 July 2006; accepted 10 July 2006 Abstract Several sociological, health and conservation arguments request a correct labelling of seafood products. Nowadays, molecular genetics is a useful tool for food chain traceability, particularly in regards to species identification. Among the variety of PCR- based molecular markers, AFLPs (Amplified Fragment Length Polymorphisms) have recently been used to investigate genomes of different complexities. This paper assesses the potential use of the AFLP technology to determine fish and seafood species in processed commercial products and domestic stocks. In particular a species database of fish, molluscs and crustaceans has been created with the aim to identify species of origin of seafood products by previously defined AFLP patterns. Different EcoRI and TaqI primer combinations were selected from 20 screened combinations in relation to the total number of detected fragments and polymorphic ones. Most informative combinations were E32/T32, E32/T33, E33/T33, E33/T37, E33/T38, E40/T33, E40/T37, E42/T32, E42/T37. The comparison of informative markers between unknown frozen or fresh products and reference samples has enabled the accurate identification of 32 different species. The taxonomic characterization has been performed either at the species or at the population level depending on the number of available individuals. AFLP variation at the population level is particularly helpful for the stock traceability of domestic strains. Size homoplasy was also investigated in one species to assess the rate of non- homologous comigrating fragments and to detect additional polymorphic markers to be used in stock identification. Results of Band Sharing Index (BSI) and percentage of polymorphic fragments are presented and are discussed in relation to the wide applicability of AFLPs both for fish and seafood safety and authenticity testing in such fields as food traceability and restocking management. The database, available upon request at nonnis@biol.unipr.it, will be continuously updated. © 2006 Elsevier B.V. All rights reserved. Keywords: Molecular biotechnology; Fingerprinting; Food safety; Traceability; Authenticity testing; Homoplasy 1. Introduction Several sociological, health and conservation argu- ments request the correct labelling of seafood products. The frequent practice of mislabelling involves such questions as truth in advertising, species substitution, consumer protection and management of depleted stocks and their monitoring (Marko et al., 2004). It is crucial that products be identified and examined in each step from fishing area and fish farms to trade and selling (Asaro, 2004). The precautionary measures are Aquaculture 261 (2006) 487 – 494 www.elsevier.com/locate/aqua-online ⁎ Corresponding author. Tel.: +39 521 905643; fax:+39 521 905657. E-mail address: nonnis@biol.unipr.it (F. Nonnis Marzano). 0044-8486/$ - see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.aquaculture.2006.07.010