Lep`i*do*si"ren (-sī"r&ebreve;n), n. [Gr. lepi`s -i`dos, a scale + seirh`n a siren.] (Zoöl.) An eel- shaped ganoid fish of the order Dipnoi, having both gills and lungs. It inhabits the rivers of South America. The name is also applied to a related African species (Protopterus annectens). The lepidosirens grow to a length of from four to six feet. Called also doko.