Experimental Assessment of a New rDNA-Based Method for the Identification ofMerluccius capensisandMerluccius paradoxusin Commercial Products

There has been great interest in the identification of Cape hakes, Merluccius capensisand Merluccius paradoxus, by non-morphological methods. The information provided by a ribosomal DNA-based method will allow investigators to precisely identify the species of Cape hake in commercial samples. The first test consisted in the PCR amplification of a 193 bp fragment from the ITSl-rDNA to assess the presence of DNA from hakes. Positive tests were followed by a second test consisting of the amplification and digestion of the PCR fragment from the ITS1 sequence, to determine the identity of the commercial species. A single restriction enzyme provided full diagnosis of the species present in the samples. Since this new method is simple, reliable, and reproducible and can be performed in a working day, it allows the genetic traceability of Cape hakes across the food chain. This could also help management of the fisheries.