[Trypanorhyncha cestodes parasitic in blackfin goosefish, Lophius gastrophysus Miranda-Ribeiro, 1915 purchased in the State of Rio de Janeiro, Brazil].

The aim of this study was to determine the cestodes species of the order Trypanorhyncha that parasite the blackfin goosefish, Lophius gastrophysus Miranda-Ribeiro, 1915 purchased from fishermen, markets and exportation fish industries from municipalities of Cabo Frio, Niterói, Duque de Caxias and Rio de Janeiro, emphasizing their parasite indexes, sites of infection and higienic-sanitary importance. Eighty seven specimens of L. gastrophysus were necropsied from March 2000 to December 2005. Forty one fish (47%) were parasitized by metacestodes of Trypanorhyncha. The collected species were Tentacularia coryphaenae, Nybelinia sp., Mixonybelinia sp. and Progrillotia dollfusi. Most of the parasitized fish (92.7%), presented metacestodes of Trypanorhyncha, in the abdominal muscles and in muscles of commercial importance (lateral back-dorsum), belonging to the species T. coryphaenae, Nybelinia sp., Mixonybelinia sp. Only three (7.3%) fish specimens did not present trypanorhynch metacestodes in the muscles, two of them were parasitized by Nybelinia sp. on the mesentery and the celomatic cavity and the other by P. dollfusi on the celomatic cavity. On some individuals, Mixonybelinia sp. caused equimotic hemorragic lesions on the fascia of the abdominal muscles. The presence of Trypanorhyncha metacestodes in the muscles does not represent a risk of infection for humans, but they have a negative effect on fish aesthetics because of the repugnant aspect, causing consumer rejection and the prohibition for commercial purpose by sanitary inspectors. Parasites of the order Trypanorhyncha are recorded in L. gastrophysus for the first time.