First taxonomical analyses of pike populations (Esocidae, Esox) in Friuli Venezia Giulia (Northeast Italy)

Recent studies have addressed to the taxonomical characterization of Italian pike as a new species named Esox cisalpinus, which differs from the European Esox lucius. A taxonomical study of the pike features in the Friuli Venezia Giulia region (Northeast Italy) is here presented, since previous studies did not consider this area which could represent an overlapping zone for the two species. Main meristic characters were investigated, and genetic analyses were carried out using molecular marjers. Our results conform the genetic separation from the E. lucius, while among meristic characters only the number of lateral-line scales differs between the species. E. cisalpinus was observed in most of the investigated sites, except for an isolated lentic habitat where E. lucius was found. As E. cisalpinus is likely autochthonous in friuli venezia Giulia as in other Italian regions, we highlight the requirement of furtheranalyses in order to clarify if hybridization can occur and to plan appropriate management safeguards for native populations.