RESUMO
Kingfishers (Alcedinidae Rafinesque) are common inhabitants of wetlands and are known to be definitive hosts to a wide range of digeneans that parasitize fish as second intermediate hosts. Among these digeneans, members of the Diplostomidae Poirier, 1886 (diplostomids) are particularly common. Recent studies of diplostomids collected from kingfishers have revealed that they are probably more diverse than currently known. This particularly concerns the genera Crassiphiala Van Haitsma, 1925 and Uvulifer Yamaguti, 1934. In the present work, we studied seven diplostomid taxa from kingfishers in Brazil, the USA and the Philippines. Partial DNA sequences of the nuclear large ribosomal subunit (28S) and mitochondrial cytochrome c oxidase I (cox1) genes were obtained, and 28S sequences were used to study the phylogenetic interrelationships of these diplostomids. We provide the first DNA sequences from Uvulifer semicircumcisus Dubois et Rausch, 1950 and a member of Subuvulifer Dubois, 1952. Pseudocrassiphiala n. gen. is erected for a previously recognized species-level lineage of Crassiphiala and a new generic diagnosis of Crassiphiala is provided. Crassiphiala jeffreybelli n. sp., Crassiphiala wecksteini n. sp. and Pseudocrassiphiala tulipifera n. sp. are described, and a description of newly collected, high-quality specimens of Crassiphiala bulboglossa Van Haitsma, 1925 (the type-species of the genus) is provided.
Assuntos
Trematódeos , Animais , Filogenia , Peixes/parasitologia , Mitocôndrias , BrasilRESUMO
Sphincterodiplostomum is a monotypic genus of diplostomid digeneans that parasitize fish-eating birds in the neotropics. The type species Sphincterodiplostomum musculosum has a unique, dorsal, tubular invagination in the opisthosoma with a muscular sphincter. Whereas larvae of S. musculosum are relatively commonly reported in Neotropical fish helminth surveys, adult specimens from birds are rarely collected. Prior to our study, no DNA sequence data for S. musculosum were available. Our molecular and morphological study of mature and immature adult Sphincterodiplostomum specimens from three species of birds and one species of crocodilian revealed the presence of at least two species of Sphincterodiplostomum in the neotropics. We provide the first molecular phylogeny of the Diplostomoidea that includes Sphincterodiplostomum. In addition, this is the first record of S. musculosum from caimans, along with the first record of fully mature adult S. musculosum from green kingfisher Chloroceryle americana. The new species of Sphincterodiplostomum (Sphincterodiplostomum joaopinhoi n. sp.) can be morphologically distinguished from S. musculosum based on the anterior extent of vitelline follicles, narrower prosoma, substantially smaller holdfast organ and structure of tegumental spines. Our data revealed 0.7% interspecific divergence in 28S and 10.6-11.7% divergence in cox1 sequences between the two Sphincterodiplostomum species.