Mormyrus longirostris, commonly referred as the eastern bottle-nosed mormyrid, is a medium-sized fish species belonging to the elephant-snout fish family Mormyridae. It was originally described by Wilhelm Peters in Monatsberichte der Akad. Wiss. Berlin, 1852. This species grows to a maximum length of 75 centimetres (30 in) and can weigh up to 10 kilograms (22 lb). The dorsal fin is more than twice the length of the anal fin. The dorsal origin is nearer to the tip of the snout than to the caudal fin base.