Petrocephalus ansorgiiPetrocephalus ansorgii, the Agberi mormyrid, is a species of electric fish in the family Mormyridae, found in Africa: on the Upper and Lower Niger, the Bénuoé, and the coastal rivers of Nigeria.SizeThis species reaches a length of.EtymologyThe fish is named in honor of English explorer and collector William John Ansorge, who collected the holotype specimen.