A new species of Euzetia (Monogenea: Euzetiinae) on the gills of Rhinoptera bonasus (Rhinopteridae) from Ciudad del Carmen, Campeche, México.

Euzetia lamothei n. sp. (Monogenea: Euzetiinae) is described from the gills of the stingray, Rhinoptera bonasus, collected from marine waters near Ciudad del Carmen, Campeche, Mexico. The species is assigned to Euzetia Chisholm and Whittington, 2001 because it has a haptor with 10 peripheral loculi and 1 central loculus ? anked by 2 lateral loculi. The species described herein can be distinguished from the only known member of the genus, E. occultum, by the morphology of the male copulatory organ, the vas deferens sigmoid, and the presence of a vaginal chamber. Euzetia lamothei n. sp. was found on 1 of 7 R. bonasus (14%). This species is the ? rst record of a member of the genus from the neotropics, the ? rst from Mexico, and the second report of a monocotylid from Rhinoptera.