Species
The Barbus genus belongs to the Cypriniformes order, the Cyprinidae family and includes a large number of species, widespread in Europe, Asia and Africa. In Italy, all authors (Tortona, 1970; Gandolfi et al, 1991 Zerunian, 2002) agree that there are at least two native species: the Common Barbel (Barbus plebejus - and Southern Barbel - Barbus meridionalis sin. B. caninus ). A debate is still in progress on the systematic position of the central and southern populations reporting the presence of a third species, the Tiber Barbel - Barbus Tyberinus - morphologically very similar to the Southern Barbel of the Po-Veneto district. Italian native species have become increasingly rare during the last years. The updated IUCN Red List (Rondinini et al., 2013), suggests new risk categories for the two species. In particular, with respect to the previous lists based on subjective evaluations of individual researchers (Zerunian, 2007) the updated list assesses the risk status of the Common Barbel to VU (vulnerable) and the risk status of the Southern Barbel from VU to EN (endangered). These changes justify interventions proposed in this work with special attention to breeding practices which are now become a prerequisite for rapid population decline species. If in the past, the assumed low level of risk might have not asked for immediate support breeding interventions, nowadays, threats and the constant quality / quantity decline of the populations of both species in Emilia Romagna, do not justify the precautionary approach proposed by Zerunian (2004) in order to avoid the restocking with hybrids. It is the responsibility of the project leaders to operate a strict morphological phenotypic and genetic selection of specimens to be used for reproduction purposes through molecular characterization. An updated demographic quantification of B. plebejus and meridionalis populations in the provinces of Parma, Piacenza and Reggio Emilia is currently not available. The censuses of the two species are in fact carried out randomly in the course of assessments on salmonid populations in the mountain stretches or during environmental assessments. A quantitative estimate of the current size of the populations of the two species can therefore be obtained almost exclusively from grey literature and the experience of the researchers fully aware of the sharp decline suffered by the species over the years.
Past data are available in the fish maps, which, however, are outdated (dating back to more than fifteen years ago). An update can be extrapolated from qualitative or semi-quantitative ichthyologic monitoring, such as that carried out for some plans of SCIs / SPAs management in 2011 (in the SCI IT4030013 and IT4030023) or in specific local studies (e.g. in the vicinity of the project ichthyologic plants). Based on the personal experience of the researchers it is worth pointing out that from the demographic point of view, where present, the populations of B. plebejus and meridionalis are constituted by a limited number of specimens, able to move in large areas within different streams and rivers for different hydrological regimes. An estimate of semi-quantitative type but definitely constant across streams and rivers where the species are present, quantifies the populations in a number of specimens ranging between 1 and 5 (category "rare") and 6 and 10 (category "poor") for about 400 square meters of watercourse. In the last five years largest populations have never been identified, with the exception of a single population of B. plebejus in the upper reach of the Taro river in Piane Carniglia (about 20 specimens along an even stretch of the river covering approximately 300 square meters).