“…Pacu, Piaractus mesopotamicus (Holmberg, 1887), is an important sport and table fish in South America (Oliveira et al, 2004;Queiroz et al, 2005) that is farmed in aquaculture systems (Oliveira et al, 2004;Queiroz et al, 2005;Urbinati et al, 2013;Valladão et al, 2016). Its parasitic fauna is known (Costa, 1963;Boeger et al, 1995;Martins and Urbinati, 1993;Tavares-Dias et al, 2001;Martins and Onaka, 2004;Campos et al, 2009;Campos et al, 2011;Franceschini et al, 2013). It is common the reports of mortality of pacu affected by these parasites (nematodes and monogeneans) in the Brazilian fish farms.…”