Widening the geographical distribution of Pimelodus mysteriosus Azpelicueta 1998 (Siluriformes: Pimelodidae) to the upper Paraná River, with diagnosis for syntopic congeners

Pimelodus mysteriosus Azpelicueta 1998, previously known only from the lower Paranaand Paraguay River basins, has been also recorded in the upper ParanaRiver floodplain. The only congeners occurring in syntopy with P. mysteriosus in the upper ParanaRiver basin are P. maculatus and P. ornatus. New diagnostic characters between P. mysteriosus and P. maculatus are provided.