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

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.