Parspina papernai n. sp. is described from the intestine of Iheringichthys labrosus from the reservoir of the Itaipu Binational Hydroelectric Power Station, State of Parana´, Brazil. The new species is characterized by and easily distinguished from the other 2 species in the genus by having the distribution of vitellaria restricted to the hindbody, with follicles extending in a transverse band from the anterior margin of the testes to the posterior portion of seminal vesicle. The new species differs in egg size from Parspina bagre and from Parspina argentinensis by having a ventral sucker smaller than oral sucker and in egg size.