Anthropogenic changes in the freshwater fish fauna of Italy, with reference to the central region and Barbus graellsii, a newly established alien species of Iberian origin

In a survey of the west-central Italian rivers Ombrone, Fiora, Albegna and Bruna, among established exotic species, the Iberian barbel Barbus graellsii was recorded in Italian fresh waters for the first time. Morphological identification was supported by comparison of cytochrome b sequences with those from related barbel species. Other exotics of particular note were Barbus barbus. Pseudorasbora parva and Leuciscus cephalus, together with the Padano-Venetian Chondrostoma genei and Padogobius bonelli. Native species still present included Leuciscus lucumonis, Telestes muticellus, Rutilus rubilio and Padogobius nigricans, but were now more restricted to upper reaches and smaller watercourses. The deleterious effect of alien species on native forms is discussed with particular reference to probable competition between C. genei and L. lucumonis, and between the two gobies. The checklist of species introduced to the fresh waters of Italy is now, updated to 34. For the Italian freshwater fish fauna in general, the conservation status of three native species (Acipenser naccari, Salmo marmoratus and Knipowitschia punctatissima) has been improved but five species are believed to he at risk (Salmo carpio, L lucumonis, Scardinius scardafa, Gobio benacensis and P. nigricans) and four anadromous species (Petromyzon murinus, Lampetra fluviatilis, Acipenser sturio and Huso huso) no longer breed in Italian fresh waters. The processes of change in the composition of the Italian freshwater fish fauna as a whole may be summarized as successively 'padanization', 'danubization' and now 'globalization'. (C) 2001 The Fisheries Society of the British Isles