Identification of Mediterranean Diplodus spp. and Dentex dentex (Sparidae) by means of DNA Inter-Simple Sequence Repeat (ISSR) markers

The aim of this paper was to test the effectiveness of Inter-Simple Sequence Repeat (ISSR) technique in detecting specific molecular markers to genetically discriminate some species of teleost fish. As model species, we used four Mediterranean sea bream species (i.e. Diplodus annularis, D. puntazzo, D. sargus sargus, and D. vulgaris), and the common Mediterranean dentex Dentex dentex. Furthermore, the occurrence in our samples of two partially albino sparids (suspected, on a morphological basis, to probably belong to D. sargus sargus and to D. dentex, respectively) allowed ISSRs to be tested on doubtful specimens. Eight ISSR primers produced 95 out of 97 scorable polymorphic loci with a large number (63) of species-private bands. Maximum parsimony analysis, ΔK statistics, and assignment test were consistent in separating the five species and solving the taxonomic position of specimens of dubious attribution. The results obtained evidence the usefulness of ISSR markers in specimen and species identification, particularly when the morphological traits of fish make the classification problematic.