Systematic status of Manaosia bracodemoca Woodland, 1935 and Paramonticellia itaipuensis Pavanelli et Rego, 1991 (Eucestoda: Proteocephalidea), parasites of Sorubim lima (Siluriformes: Pimelodidae) from South America

Type material of the proteocephalidean cestodes Manaosia bracodemoca Woodland, 1935 and Paramonticellia itaipuensis Pavanelli et Rego, 1991 (both monotypic genera) as well as recently collected material of the latter species are redescribed. A close similarity between both species was observed: the shape of scoleces is identical, both possess a globular scolex with hidden suckers, a well-developed circular, horseshoe-shaped musculature surrounding suckers; the measurements of both taxa are also similar (scolex, suckers, young proglottides). Both cestodes possess a medullary ovary crossing the dorsal muscle layer and ending in the dorsal cortex, the testes are in the dorsal cortex and the cortical vitellarium is laterally situated. Both species parasitize the same fish host. Therefore Paramonticellia is considered a junior synonym of Manaosia and Paramonticellia itaipuensis becomes a junior synonym of Manaosia bracodemoca. An emended diagnosis of Manaosia, which is a monotypic genus, is provided. In 1991, Pavanelli and Rego described two new genera and three new species: Paramonticellia itaipuensis, Goezeella nupeliensis and Nupelia portoricensis, and another species Spatulifer cf. maringaensis Pavanelli et Rego, 1989, in the siluriform fish Sorubim lima (Schneider) from the Parana River basin (Pavanelli and Rego 1989, 1991). De Chambrier and Vaucher (1999) synonymised Goezeella nupeliensis with Paramonticellia itaipuensis. New material of all these species was obtained from the same host during field expeditions in both the Parana and Amazonian basins. During studies of Woodland’s type material deposited in the Natural History Museum in London, a similarity was noticed between the monotypic genera Paramonticellia Pavanelli et Rego, 1991 and Manaosia Woodland, 1935, the latter being considered as genus inquirendum (Freze 1965, Rego 1994, Rego et al. 1999). The aim of this study was to revise the type material of both genera and compare it with recently collected specimens in order to clarify their generic and specific status. MATERIALS AND METHODS Immediately after dissection of fish, the recently collected worms were fixed with a hot 4% v/v neutral formaldehyde solution, then stained with Mayer’s hydrochloric carmine solution, dehydrated in an ethanol series, cleared with Eugenol (clove oil), and mounted in Canada balsam. Pieces of strobila were embedded in paraffin wax, cross sectioned (thickness 12–15 μm), stained with Weigert’s haematoxylin and counterstained with 1% eosin B according to the methods recently published by de Chambrier (2001). All measurements are given in micrometres. Abbreviations used in descriptions: x = mean, n = number of measurements, CV = coefficient of variability (%), OV = ovary width to proglottis width ratio, PG = position of the genital pore to proglottis length ratio (%), PC = cirrus pouch length to proglottis width ratio (%), MT = type material. Material is deposited at the Natural History Museum (MHNG), Geneva, Switzerland. Material examined Syntype material of Manaosia bracodemoca Woodland, 1935 from the Natural History Museum, London: BMNH 1965.2.24.106-108, field number Amaz 8, 1 whole mount preparation, 1 slide of frontal scolex sections, 7 slides of transversal scolex sections. The whole mount preparation bears 5 pieces of Manaosia and probably one piece of Spatulifer cf. maringaensis. Type material of Paramonticellia itaipuensis Pavanelli et Rego, 1991 from the helminthological collection of the Instituto Oswaldo Cruz, Rio de Janeiro: holotype IOC 32.560a, paratypes IOC 32.560 b–c, IOC 32.561 a–b, Rio Paraná, Itaipu and Porto Rico, Paraná, Brasil. Goezeella nupeliensis Pavanelli et Rego, 1991: holotype IOC 32.562a, paratypes IOC 32.562b–c, IOC 32.563a, Rio Paraná, Itaipu and Porto Rico, Paraná, Brasil (= P. itaipuensis; see de Chambrier and Vaucher 1999). Recently collected material (deposited in MHNG): Rio Paraná, Campichuelo, Province Itapua, 28.02.1987, 17909 INVE; Rio Paraguay, San Antonio, Central Province, 28.10.1989, 17908 INVE, 27.11.1993, 19354 INVE, 04.11.1995, 21855 INVE; Itacoatiara, Rio Amazonas, Brasil, 03.10.1995, 32813 INVE. FOLIA PARASITOLOGICA 50: 121–127, 2003 Address for correspondence: A. de Chambrier, Muséum d’Histoire Naturelle, P.O. Box 6434, CH-1211 Geneva 6, Switzerland. Phone: ++41 22 418 6319; Fax: ++41 22 418 6301; E-mail: [email protected]