Nomimoscolex suspectus n. sp. (Eucestoda: Proteocephalidea: Zygobothriinae) with morphological and molecular phylogenetic analyses of the genus

Abstract

We describe a new species of Nomimoscolex from the Amazon siluriform fishes Brachyplatystoma filamentosum, B. flavicans and B. vaillanti. It differs from N. piraeeba in a lower mean number of testes, the paramuscular position of the vitelline follicles, the ovarian width/proglottis width ratio and the cirrus-pouch length/proglottis width ratio. Protein electrophoresis assays performed for 25 enzymatic systems showed that specimens of N. suspectus n. sp. from the three host species form a homogenous population which was genetically isolated from N. piraeeba and N. dorad. Moreover, the latter two species, synonymised by Rego (1991) because of their close morphological similarity, could be separated at eight loci. We thus restore N. dorad as a valid species. We finally examined the composition of the genus Nomimoscolex using DNA sequences from the 5.8S rRNA, ITS-2 and 28S rRNA nuclear ribosomal genes and a matrix of 24 morphological characters. Phylogenetic relationships were inferred for nine species of the genus, five members of other monticelliid genera and two outgroup species. The results of the phylogenetic analyses performed on morphological and molecular characters converged with those from allozyme studies and showed that N. suspectus, N. piraeeba and N. dorad clustered in a distinct clade that excluded other members of the genus. We therefore recognised them as an aggregate of species to reflect an isolation supported by both morphological and genetic data. Because relationships among the remaining Nomimoscolex representatives and other genera were generally poorly resolved, regardless of the database analysed, no action was taken to reorganise them into alternative groupings.

Two new genera and two new species of proteocephalidean tapeworms (Eucestoda) from reptiles and amphibians in Australia

“…De chambrier and Vaucher (1997) observed in this species that the uterine stem is in the ventral cortex and develops diverticula within the medulla as it is also the case in Endorchis piraeeba Woodland, 1934, another species parasitic in pimelodid catfishes in South America. This feature was also observed in Harriscolex kaparari (Woodland, 1935), Endorchis auchenipteri de chambrier et Vaucher, 1999, Gibsoniela meursaulti de chambrier et Vaucher, 1999, Nomimoscolex chubbi (Pavanelli et takemoto, 1995 and N. suspectus Zehnder, de chambrier, Vaucher et Mariaux, 2000, (Woodland 1934a, 1935b, Pavanelli and takemoto 1995, chambrier and Vaucher 1997, 1999, Zehnder et al 2000.…”

“…it is very rare to observe the internal layer of longitudinal musculature to be absent laterally. this characteristic has been reported for three species of unrelated subfamilies (gangesiinae and Zygobothriinae), namely Nomimoscolex dorad (Woodland, 1935), N. suspectus Zehnder, de chambrier, Vaucher et Mariaux, 2000and Postgangesia orientalis akhmerov, 1969(Woodland 1935, Zehnder et al 2000, de chambrier et al 2003. this feature is also reported for Australotaenia hylae as well as for the new Australotaenia species described herein and Vandiermenia beveridgei.…”

“…gladiate spinitriches on the middle part of the pyramidal apex surface. both parasites of Brachyplatystoma filamentosum (Pimelodidae) (Woodland 1934a,b, 1935a, de chambrier and Vaucher 1997, Zehnder et al 2000. all these also possess a cortical uterine stem with the medullary development of uterine diverticula, similarly as it is in V. beveridgei.…”

Morphological and genetic differentiation of Rodentolepis straminea (Goeze, 1752) and Rodentolepis microstoma (Dujardin, 1845) (Hymenolepididae)

“…Alternative methods to morpho-anatomy are essential for testing the validity of closely related or sibling species. Isoenzymes proved to be a powerful tool for clarifying the taxonomic status of closely related species in various groups of cestodes, particularly: Renaud et al (1983) (bothriocephalids); Renaud and Gabrion (1988) (cyathocephalids); de Chambier et al (1992); de Chambier and Vaucher (1994);Hanzelova et al (1995); Snabel et al (1994);Zehnder et al (2000) (proteocephalids); Ba et al (1993); Baverstock et al (1985) (anoplocephalids); and Montgomery et al (1987) (hymenolepidids) (see also Beveridge 1998 andChilton 1999, for reviews). In our case, the taxa considered are sympatric.…”

Nomimoscolex pertierrae n. sp. (Eucestoda: Proteocephalidea), a parasite of Pseudoplatystoma corruscans (Siluriformes: Pimelodidae) in Brazil and redescription of N. sudobim Woodland, 1935, a parasite of P. fasciatum

“…sudobim Woodland, 1935;N. suspectus Zehnder, de Chambrier, Vaucher & Mariaux, 2000;and N. touzeti de Chambrier & Vaucher, 1992(See Woodland 1933, 1934a,b, 1935aBrooks & Deardorff, 1980;Rego, 1989;Rego & Pavanelli, 1990;de Chambrier & Vaucher, 1992;Gil de Pertierra 1995, 2002, 2003Pavanelli & Takemoto 1995;Zehnder et al, 2000).…”