RAPD-PCR method is now widely employed in genetic research and is a powerful asset when trying to identify species. In the present work, RAPD genetic markers were obtained for distinguishing between three species of the genus Gobio that show substantial morphological resemblance. Different profiles were observed: six species-specific markers were detected for G. gobio, four for G. kesslerii and nine for G. uranoscopus. These markers were reproducible, dependable and very helpful in differentiating between these species.
The genus Gobio in Italy was represented by the endemic species G. benacensis. The original distribution of this species was the Padano-Venetian district, but since a long time it was introduced in central Italy. Introductions of alien species to Italy during the last 10 years brought the sudden introduction of the Danubian G. gobio. Genetic and morphological analyses revealed the extensive presence of G. gobio, which rapidly colonised several rivers in Italy causing the progressive decline of G. benacensis, which now should be considered as an endangered species. Among examined populations those found in the Tagliamento River and transplanted in the Ombrone River represent genetic reservoirs of this species which will probably disappear in northern Italy.