The crab Percnon gibbesi and the mollusc Aplysia dactylomela are recorded for the first time from the Taranto Gulf (Italy, Ionian Sea). Both alien species have been widely reported in the Mediterranean and have established populations in Greece and Sicily. The presence of a few specimens induces us to think that only lately these two species expanded their distributional range and that new stable populations will probably soon settle in the whole area.