Two Unusual New Genera of Paramphistomidae (Trematoda, Digenea) From Freshwater Fish of the Brazilian Amazon

Abstract

Two new genera and species of Paramphistomidae (Tremadota, Digenea) are described from freshwater fish of the Brazilian Amazon. Anavilhanatrema robusta gen. et sp. nov. is characterized as having a cylindrical body with an anterior expansion, small suckers, a small cirrus sac, large lobate testes, a lobate ovary, long ceca and extensive vitellaria. Pacudistoma turgida gen. et sp. nov., on the other hand, is distinguished by having a stout, cylindrical body, a large oral sucker with internal diverticula, a large genital sucker, smaller lobate testes, a spherical ovary, long ceca and relatively extensive vitellaria. Both species appear to be host specific with A. robusta found in Pristobrycon striolatus (STEINDACHNER) while P. turgida occurus in Hyleus pacu (SCHOMBURCK).

New Species of Gieysztoria (Platyhelminthes, Rhabdocoela) from Peruvian Amazon Floodplain with Description of their Stylet Ultrastructure

“…Most of the well-known Platyhelminthes from the Amazon basin belong to the parasitic classes (Neodermata): Cestoda, Trematoda and Monogenea ( e.g. Thatcher, 1993;Carvalho et al, 2001;Marques et al, 2003;Belmont-Jegu et al ;2004;Rego, 2004) whereas the free-living Platyhelminthes are almost unknown. Presently only four species have been mentioned from the Amazon river (floodplain and tributaries): Xenostenostomum microstomoides Reisinger, 1976, Dugesia fissipara (Kennel, 1888 Ball, 1974 (Marcus, 1948) captured near the Amazon estuary, and more recently, Sergia sp.…”