Occurrence of the Parasite Myosaccium ecaude in Thread Herrings from the Gulf of Tehuantepec, Mexico

Thread herrings (Opisthonema spp.) are economically important fish species in the Tropical Eastern Pacific. Knowledge of parasitofauna commercially exploited is useful as it can increase our understanding biology and ecology. However, knowledge parasites Opisthonema spp. limited. During a fisheries exploration survey April 2022, samples bulleri O. libertate were collected from three oceanographic stations Gulf Tehuantepec Mexican Parasitological analysis these materials uncovered four parasite species: Myosaccium ecaude (Trematoda), Cribromazocraes sp. (Monogenea), Pseudoterranova (Nematoda), an unidentified crustacean family Pennellidae (Copepoda). All appeared rarely, except for M. ecaude, which reached prevalence 100%. The median intensity infection was significantly higher than libertate. We analyzed relationship between parasitic host traits (fork length, body weight, age). Only weight showed significant positive association with intensity. Future studies required to analyze possible effects seasonality, locality, ontogeny on occurrence thread