The primers used for amplifying the 16S rRNA mitochondrial gene described by Palumbi et al. (1991) were not useful for obtaining part of this gene in T. truncatus. Therefore, it seemed that they were not useful for vertebrates. These primers have proven to be very useful in a variety of invertebrates (Palumbi et al., 1991; Rawson and Hilbish, 1995; pers. obs.). In the case of the BDR region of the Cytochrome-b gene, the primers tested, described by Unseld et al. (1995) for a very conservative region of vertebrate species, were useful for amplifying this gene in T. truncatus. The fragment obtained for this species was close to 123 bp, the size observed for tunnids (Fig.1).