Megacoelium plecostomi Szidat, 1954

Material deposited: MACN-Pa 609 (type material and voucher material).

Host: Hypostomus plecostomus (= Plecostomus plecostomus) (type host); Hypostomus commersoni *.

Localities: La Plata River in front to Buenos Aires City, Uruguay River in front of Santo Tomé City, Corrientes Province [type locality not assigned by Szidat (1954)]; Paraná-Guazú River**, Entre Ríos Province.

Site of infection: Stomach, anterior part of intestine.

References: Szidat (1954), Arredondo (2013).

Remarks: New host and locality record. Szidat (1954) indicated the presence of Megacoelium plecostomi in Plecostomus plecostomus, but according to Froese & Pauly (2016) and Almirón et al. (2015) this species is not present in continental waters of Argentina. Probably, due to similarity among them, the record of Hypostomus plecostomus by Szidat (1954) corresponds to Pterygoplichthys anisitsi which inhabits the Paraná River basin.