Choledocystus cf. elegans (Travassos, 1926) Ruiz, 1949

Hosts (prevalence; range): P. platensis (26/35; 1–6).

Site of infection: small intestine and lungs.

Stage: adult.

Type host and type locality: L. latrans (= L. ocellatus), S„o Paulo, Brazil.

Comments: Choledocystus elegans was described as Glypthelmins elegans by Travassos (1926). After, Pereira & Cuocolo (1941) established the genus Choledocystus, and Ruiz (1949) considered G. elegans as C. elegans due to a set of features such as tegument with spines from anterior to posterior end, wide pharynx, large caeca reaching posterior region, globular cirrus sac anterior to acetabulum, dextral ovary, and Y-shaped excretory vesicle with branches reaching the testes; the most of these features were observed in our specimens which lead us to determine C. cf. elegans . However, several taxonomic debates have concerned these plagiorchioids ( Choledocystus, Glypthelmins, and Rauschiella); according to Razo-Mendivil et al. (2006) some characters such as ovary position, features of spines in tegument, the type of excretory vesicle, and the extension of uterine loops can help to distinguish these genera. Considering these complex taxonomic relations among plagiorchiids, we encourage species confirmation with molecular and SEM analyses in some cases. This is the first record of C. cf. elegans in P. platensis; other records for this parasite were in L. latrans, Leptodactylus labyrinthicus (Spix) and R. marina from Argentina and Brazil (see Campi„o et al. 2014) and Leptodactylus paraensis Heyer from Pará State, Brazil (Gomes et al. 2017).