Expanding on : a new species of from North America and the Caribbean based on molecular and morphological data.

Members of the genus mature in accipitrids, particularly osprey, , with metacercaria causing Black Spot Syndrome in reef fishes. In most of the world, only the type species, (Creplin, 1842) has been reported. Recent molecular studies in the Western Atlantic, Mediterranean and Persian Gulf reveal multiple species of , but have relied on 28S rDNA, mainly from metacercariae, which limits both morphological identification and resolution of closely related species. Here we combine nuclear rDNA with mitochondrial sequences from adult worms collected in osprey across North America and the Caribbean to describe species and elucidate life cycles in . A new species described herein can be distinguished from based on overall body shape and size. Phylogenetic analysis of the whole mitochondrial genome of indicates a close relationship with . We conclude that at least 3 species of are present in the Americas and 2 others are in the Old World. Specimens in the Americas have similar or identical 28S to those in the Mediterranean and Persian Gulf, but amphi-Atlantic species are unlikely in light of divergence in cytochrome oxidase I and the lack of amphi-Atlantic avian and fish hosts. Our results provide insight into the geographic distribution and taxonomy of a little-studied trematode recently linked to an emerging pathology in ecologically important reef fishes.