Haematoloechus neivai (Travassos & Artigas, 1927) Odening, 1960

Hosts (prevalence; range): P. platensis (5/38; 1–14).

Site of infection: lungs.

Stage: adult.

Type host and type locality: L. latrans (= L. ocellatus), Rio de Janeiro, Brazil.

Comments: this digenean was described as Pnemonesces neivai by Travassos & Artigas (1927), and then Ingles (1932) placed it in the genus Haematoloechus; then, Odening (1960) proposes the genus Neohaematoloechus based on the absence of ventral sucker and considered Neohaematoloechus neivai as the type species. Recently, León- Règagnon & Topan (2018) in a taxonomic revision of the genus Haematoloechus proposed the new combination Haematoloechus neivai as valid species considering phylogenetic evidence, however there were not included molecular data of species historically considered of the genus Neohaematoloechus . Haematoloechus neivai presents a brown body due to host’s blood in intestinal caeca and numerous eggs in branches of uterus. Moreover, we observed in our specimens other diagnostic features such as absence of ventral sucker, oval testes in coincident zones, and a very developed Mehlis’s gland which is larger than the rounded ovary. Also, uterine loops are replete with eggs and distributed predominantly in the extracaecal region reaching the level of oral sucker where is the genital pore (Travassos & Darriba 1930; Dobbin Jr. 1957). Pseudis platensis has previously been recorded as host for H. neivai by Travassos & Freitas (1940) in Mato Grosso, Brazil.