| wallinia chavarriae n. sp. (trematoda: macroderoididae) in astyanax aeneus (gunther, 1860) and bryconamericus scleroparius (regan, 1908) (osteichthyes: characidae) from the area de conservación guanacaste, costa rica. | wallinia chavarriae n. sp. is described from the small-bodied characids astyanax aeneus and bryconamericus scleroparius in the area de conservación guanacaste, northwestern costa rica. the species differs from w. valenciae in possessing an acetabulum that is smaller than the oral sucker and vitelline follicles that are ovoid or rounded rather than elongate and tubular. detailed comparison between these 2 species is handicapped by the less than satisfactory condition of the type and only museum s ... | 2002 | 12053949 |