A hotspot of xenodiversity: first evidence of an assemblage of non-native freshwater turtles in a suburban wetland in Central Italy.
The present study reports on a case of high richness in an assemblage of non-native freshwater turtles in a suburban wetland of Tyrrhenian Central Italy (Torre Flavia Nature Reserve), providing evidence for first observations of species at regional, national and continental levels. Following a standardized sampling procedure, 54 specimens belonging to seven taxa (ten taxa, including subspecies) were sampled. These included Trachemys scripta (overwintering in the nest of a juvenile, corroborating its reproduction in the wild), Graptemys pseudogeographica, Pelomedusa olivacea (first observation recorded for Europe), Pseudemys concinna, Pseudemys nelsoni, Mauremys sinensis and an unclassified Kinosternidae (Kinosternon subrubrum subrubrum vel Sternotherus odoratus; first observation recorded for Europe at the family level). Due to the high frequency of the most common species (Trachemys scripta: >80% in frequency), this non-native assemblage was characterized by high Simpson dominance, low Simpson diversity and low evenness values. This appears to be the first evidence of a local hotspot of these non-native reptiles in Europe. These relevant data and their ecological implications (e.g., alien food webs) are discussed, as well as their conservation concerns and wetland management perspectives.