New boundaries: Redefining the geographical range of a threatened fish through environmental <scp>DNA</scp> survey

Accurate data on the distribution and population status of threatened fish species are fundamental for effective conservation planning management. In this work, in order to reassess globally Evia barbel, Barbus euboicus, we undertook an environmental DNA (eDNA) survey coupled with conventional electrofishing, focusing major river basins Island proximity its known occurrence a single Evian basin (Manikiatiko stream). For comparison purposes, conducted eDNA sampling several locations geographically closest continental basin, Sperchios (Central Greece) which hosts closely related sperchiensis. Our results expand range barbel adding four new basins, apart from type locality stream (EV3)). River, where had never been located before, there was also positive signal sperchiensis within same basin. The research confirms wider geographical area, highlighting however sensitive due still very narrow distribution. biogeographical implications our study, as well potential interventions, discussed.