title: Monticellia santafesina n. sp. (Cestoda: Proteocephalidea), a parasite of Megalonema platanum (Günther) (Siluriformes: Pimelodidae) in the Paraná River basin, Argentina.
abstract: The proteocephalidean tapeworm Monticellia santafesina n. sp. is described from the siluriform catfish Megalonema platanum (Günther) (Siluriformes: Pimelodidae) in the Paraná River basin, Argentina. The new species is allocated to Monticellia La Rue, 1911 (Proteocephalidae: Monticelliinae) because of the cortical position of the testes, ovary, vitelline follicles and uterus, a globular scolex without a metascolex and uniloculate suckers. The new species differs from all other species of Monticellia (except for M. lenha Woodland, 1933) in possessing a vaginal canal opening anterior or posterior to the cirrus-sac. M. santafesina can be distinguished from M. lenha by the following characteristics: a larger body size; a weakly developed internal longitudinal musculature arranged in 15-35 slim bundles of muscle fibres; vitelline follicles not interrupted at the level of the cirrus-sac and vaginal canal, and with a few paramuscular and/or medullary follicles; the absence of large spinitriches on the anterior margin of the suckers; and the utilisation of Megalonema platanum (in the Paraná River basin) as its host, rather than Sorubimichthys planiceps (Spix & Agassiz) (in the River Amazon). Monticellia santafesina exhibits low values of prevalence (9%) and intensity of infection (1). Megalonema platanum was parasitised by two proteocephalidean cestodes, Rudolphiella cf. lobosa (Riggenbach, 1895) and the new species described in this paper.
authors.affiliation: Laboratorio de Helmintología, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Int. Güiraldes 2160, Pabellón II, 4 masculine Piso, Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina. arredondonj@bg.fcen.uba.ar
authors.forename: Nathalia J
authors.initials: NJ
authors.lastname: Arredondo
authors.forename: Alicia A Gil
authors.initials: AA
authors.lastname: de Pertierra
mesh_terms: D000818:Animals; D001118:Argentina / Q000453:epidemiology; D002397:Catfishes / Q000469:parasitology*; D002589:Cestoda / Q000033:anatomy & histology* / Q000145:classification* / Q000502:physiology; D002590:Cestode Infections / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D005393:Fish Diseases / Q000453:epidemiology / Q000469:parasitology*; D015995:Prevalence; D045483:Rivers; D013045:Species Specificity