A new species of Dadayius Fukui, 1929 (Digenea: Cladorchiidae), parasite of Symphysodon aequifasciatus Pellegrin, 1904 (Perciformes: Cichlidae) from the Purus River, Amazon, Brazil

Summary: The present paper describes a new species of Dadayius Fukui, 1929 (Trematoda, Digenea), parasite of Symphysodon aequifasciatus Pellegrin, 1904, a freshwater fish. The fish were collected from the Purus River, Amazonas State, Brazil. This new species has a long body and, different from other species of the genus, an arch-shaped ovary and a sinuous oesophagus with an ovoid bulb. This is the first record of Dadayius in cichlid fish; to date Dadayius has only been found parasitizing characid fish. © 2011 © Versita Warsaw and Springer-Verlag Wien

Neotropical Monogenoidea. 39 : une nouvelle espèce de <i>Kritskyia</i> (Dactylogyridae, Ancyrocephalinae) des uretères et de la vessie urinaire de <i>Serrasalmus marginatus</i> et <i>S. spilopleura</i> (Characiformes, Serrasalmidae) du Sud Brésil avec un

Kritskyia annakohnae n. sp. (Dactylogyridae, Ancyrocephalinae) est décrit à partir d’individus parasites des uretères et de la vessie urinaire des piranhas Serrasalmus marginatus Valenciennes, 1836 et S. spilopleura Kner, 1858 (Characiformes, Serrasalmidae) du Rio Baia, Paraná, Brésil. La nouvelle espèce est caractérisée par une protubérance sur le côté gauche du tronc, ainsi que par une pièce accessoire comprenant deux sous-unités parallèles, fusionnées aux deux extrémités, proximale et distale. Une nouvelle diagnose du Kritskyia Kohn, 1990 est proposée. En dépit d’une proposition antérieure, Kritskyia ne s’apparente pas à d’autres Dactylogyridae qui n’ont ni ancres ni barres transversales haptorales. Les connaissances actuelles sur la morphologie et la phylogénie indiquent que la perte de ces sclérites a eu lieu plusieurs fois et indépendamment dans la famille.Kritskyia annakohnae n. sp. (Dactylogyridae, Ancyrocephalinae) is described from the ureters and urinary bladder of the piranhas, Serrasalmus marginatus Valenciennes, 1836 and S. spilopleura Kner, 1858 (Characiformes, Serrasalmidae) from the Rio Baia, Paraná, Brazil. The new species is characterized by having a keel-like projection on the left margin of the trunk and an accessory piece comprising two parallel subunits, proximally and distally fused. An emended diagnosis of Kritskyia Kohn, 1990 is provided to accommodate the new species. Although previously suggested, Kritskyia is probably not closely related to other Dactylogyridae lacking haptoral anchors and bars. Present knowledge on morphology and phylogeny indicates that the loss of these sclerites has occurred independently several times within the family.</p

Cestodes in South American freshwater teleost fishes: keys to genera and brief description of species

Keys to genera of cestodes in South American freshwater teleost fishes are provided, with diagnoses of genera and short descriptions of species. Two new genera are proposed, Chambriella gen.n. for Goezeella agostinhoi Pavanelli & Santos, 1992 and G paranaensis Pavanelli & Rego, 1989, and Brooksiella gen.n. for Amphoteromorphus praeputialis Rego, Santos & Silva, 1974. Nomimoscolex magna Rego, Santos & Silva, 1974, previously species inquirenda, is transferred to the genus Proteocephalus Weinland, 1858. Goezeella nupeliensis Pavanelli & Rego, 1989 is considered a species inquirenda. Species and host lists are included

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

Rhinoxenus bulbovaginatus n. sp. is described from the nose of Salminus maxillosus (Characidae) collected in the basin of the rio Paraná, near the city of Porto Rico, state of Paraná, Brazil. The new species can be differentiated from the other three species in the genus by the morphology of the copulatory complex, vagina, and ventral anchor. The sister group relationship of the known species of Rhinoxenus was determined using techniques of Phylogenetic Systematics (Cladism). The resulting cladogram (C.I.=100%) indicates that the new species is most closely related to R. piranhus Kritsky, Boeger and Thatcher, 1988. The other two species of the genus, R. arietinus Kritsky, Boeger and Thatcher, 1988 and R. nyttus Kritsky, Boeger and Thatcher, 1988, both parasites of Anostomidae fishes, have a paraphyletic position in the cladogram, suggesting that the origin of at least one of them can not be associated to cospeciation

Infection of Oxydoras kneri Bleecker, 1862 (Pisces, Doradidae) by the Acanthocephalan Paracavisoma impudica (Diesing, 1851) Kritcher, 1957

Infection of Oxydoras kneri by the acanthocephalan Paracavisoma impudica is described. The parasites do not penetrate deeply into the host gut wall and do not reach the muscularis layers. Host reaction is minimal, consisting of limited fibrosis around the proboscides. Haemorrhages and lymphocyte infiltration are not observed, and phagocytic cells are only present occasionally. Oxydoras kneri is a newly reported host for Paracavisoma impudica