Abstract:
Specimens of a species of cyclocoelid digenean inhabiting Jacana spinosa from the Area de Conservacio´n Guanacaste,
Costa Rica, most closely resemble Haematotrephus facioi (Brenes and Arroyo, 1962) Yamaguti, 1971, in the same host
from Aranjuez, Puntarenas Province, Costa Rica, in having confluent vitelline follicles posteriorly, diagnostic of Neohaematotrophus,
and in pharynx length, ovary width, and cirrus sac on the sinistral side. The new species is also highly similar in appearance
to H. gendrei Dubois, 1959, also inhabiting a jacanid (from West Africa), which has vitelline follicles confluent posteriorly, and
extending anteriorly to the intestinal bifurcation and genital pore opening immediately posterior to the anterior margin of the
pharynx. Like H. facioi, H. gendrei has a relatively much shorter and broader cirrus sac than does the new species. Examination
of the holotype and paratype of H. facioi confirmed that the specimens from Guanacaste differ in having a longer body, a larger
ovary and eggs, and smaller testes. They also have the ovary on the sinistral rather than the dextral side of the body, genital
pore anterior to the pharynx rather than at or posterior to the level of the posterior margin of the pharynx, longer and thinner
cirrus sac, and eggs without eyespotted miracidia. Half the eggs in both specimens of H. facioi have well-developed eyespotted
miracidia, whereas the typical condition for cyclocoelids is for virtually all eggs to exhibit eyespotted miracidia. Both H. facioi
and H. gendrei are transferred to Neohaematotrophus, along with the new species.
