Trypanorhyncha cestodes of hygienic-sanitary importance infecting flounders Paralichthys patagonicus Jordan, 1889 and Xystreurys rasile (Jordan, 1891) of the Neotropical region, Brazil.

From February 2007 to July 2010, 27 specimens of Paralichthys patagonicus, and from September to December 2010, 30 specimens of Xystreurys rasile were purchased from fish markets in the municipalities of Cabo Frio and Rio de Janeiro, State of Rio de Janeiro, Brazil. The fishes were measured, necropsied, filleted, and further had their organs investigated. In P. patagonicus, 19 (70, 3 %) were parasitized with metacestodes of Trypanorhyncha species: Nybelinia erythraea, N. lingualis, Heteronybelinia nipponica, Pterobothrium crassicolle, Grillotia carvajalregorum, and Callitetrahynchus gracilis. In X. rasile, 17 (56, 6 %) were parasitized with metacestodes: N. erythraea, N. lingualis, H. nipponica, and G. carvajalregorum. The parasitological indices of prevalence, intensity, mean intensity, abundance, mean abundance, range of infection, and infection sites of each parasite species are presented. This is the first report of Trypanorhyncha cestodes parasitizing specimens of P. patagonicus and X. rasile. These cestodes were studied due to their importance during fish sanitary inspection, if one considers the harm that the repulsive aspect of infected meat causes to consumers.