Experimental assessment of a new rDNA-based method for the identification of merluccius capensis and merluccius paradoxus in commercial products

There has been great interest in the identification of Cape hakes, Merluccius capensis and 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 ITS1-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 se quence, 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. © 2004 by The Haworth Press, Inc. All rights reserved.