Neotropical Monogenoidea. 24. Rhinoxenus bulbovaginatus n. sp. (Dactylogyridae, Ancyrocephalinae) from the nasal cavity of Salminus maxillosus (Osteichthyes, Characidae) from the Rio Paraná, Paraná, Brazil

Abstract

Rhinoxenus bulbovaginatus n. sp. is describedfrom the nose ofSalminus maxillosus (Characidae) collected in the basin ofthe Rio Parana, near the city ofPorto Rico, State ofParana, Brazil. The new species can be differentiatedfrom the other three species in the genus by the morphology ofthe copu- latory complex, vagina, and ventral anchor. The sister group relationship ofthe known species of Rhinoxenus was determined using techniques ofPhylogenetic Systematics (Cladism). The resulting cladogram (Cl. =100%) indicates that the new species is most closely related to R. piranhus Kritsky, Boeger and Thatcher, 1988. The other two species ofthe genus, R. arietinus Kritsky, Boeger and Thatcher. 1988 and R. nyttus Kritsky, Boeger and Thatcher, 1988. both parasites ofAnostomidae fishes. have a paraphyletic position in the cladogram. suggesting that the origin ofat least one ofthem can not be associated to cospeciation. Key