Echinostomatidae Poche, 1926 .

Unidentified metacercariae

Hosts (prevalence; range): P. mystacalis (1/59; 45).

Site of infection: mesentery.

Stage: encysted larva.

Type host and type locality: not informed.

Comments: this metacercaria has a very small subtriangular body shape which is covered with small spines without head collar, and unidentified corpuscles were observed in the body. However, an identification more specific was hindered because these specimens are very immature. Echinostomatid trematodes can use reptiles, birds, and mammals as definitive hosts (Hamann & González 2009).