Saccocoelioides lamothei n. sp. from Dormitator latifrons (Pisces: Eleotridae) from coastal lagoons of Guerrero, Mexico

A new haploporid trematode, Saccocoelioides lamothei n. sp., is described from the intestine of the Pacific fat sleeper, Dormitator latifrons from 2 coastal lagoons of Guerrero, Mexico. The new species is characterized by the presence of diffuse eye-spot pigmentation in the forebody, 2 sac-like caeca ending pretesticularly, ventral sucker pre-equatorial and miracidium with pigmented eye-spots in eggs. It differs from all other congeneric species by having a small, pyriform to slightly elongated body, a short but conspicuous prepharynx and sac-like caeca terminating pretesticularly, an extreme posterior position of the testis, a small spherical to elongated ovary, vitelline follicles irregular in shape and size and reaching the ovary level, the uterus extending from the testicular zone to the acetabular region, with numerous relatively large eggs.