Gauchergasilus euripedesi (Copepoda, Ergasilidae) parasitizing different species of fish from two environments in southern Brazil

The parasitic copepod Gauchergasilus euripedesi (Montú, 1980) Montú & Boxshall, 2002 was described from plankton samples and specimens found in four fish species the estuarine area of Patos Lagoon, state Rio Grande do Sul (RS), Brazil. Later, one different reported parasitized with G. same locality. Species Astyanax Baird Girard, 1854 ( henseli Melo Buckup, 2006 lacustris (Lütken, 1875)) Psalidodon Eigenmann, 1911 eigenmanniorum (Cope, 1894) aff. fasciatus (Cuvier, 1819)) were collected two environments (Pintada Island, municipality Porto Alegre Itapeva Terra de Areia, RS) to investigate their parasites. copepods gill arches counted, processed, mounted permanent slides, photographed using light microscopy, or processed for observation scanning electron microscopy. Specimens P. Pintada A. by , prevalences 29.03% ), 10.34% 9.68% (P. fasciatus). Measurements obtained similar those literature, except egg sacs which larger examined present study. In addition being first report parasitizing fasciatus), results presented here also extend known geographic distribution species.