WHALLWACHSIA ILLUMINATA N. GEN., N. SP. (TREMATODA: DIGENEA: PLAGIORCHIFORMES: PROSTHOGONIMIDAE) IN THE STEELY-VENTED HUMMINGBIRD AMAZILIA SAUCERROTTEI (AVES: APODIFORMES: TROCHILIDAE) AND THE YELLOW-OLIVE FLYCATCHER TOLMOMYIAS SULPHURESCENS (AVES: PASSERIFORMES: TYRANINIDAE) FROM THE AREA DE CONSERVACIÓN GUANACASTE, GUANACASTE, COSTA RICA

摘要

A new species of digenean found in the intestines of the steely-vented hummingbird Amazilia saucerrottei and the yellow-olive flycatcher Tolmomyias sulphurescens from the Area de Conservación Guanacaste, Guanacaste, Costa Rica, resembles members of the Prosthogonimidae in having a highly lobate ovary; an elongate cirrus sac containing the cirrus, pars prostatica, and internal seminal vesicle; no external seminal vesicle; 2 fields of extracecal vitelline follicles restricted to the area between the intestinal bifurcation and testes; and uterine loops occupying all available space in the hind body. The new species differs from all other members of the family in having genital pores opening laterally to the cecum, immediately anterior to the acetabular level, and markedly oblique rather than symmetrical testes. Consequently, we propose the new genus Whallwachsia for the species. Preliminary phylogenetic assessment suggests that the species is the sister group of all other prosthogonimids.