Three tapeworm species belonging to the genus Atractolytocestus Anthony, 1958 (Cestoda: Caryophyllidea) were reported from the common carp, Cyprinus carpio L., 1758 in the People's Republic of China so far: Atractolytocestus sagittatus; Atractolytocestus tenuicollis; and Atractolytocestus huronensis. In this study, we identified a putatively new tapeworm species in common carp from the Danjiangkou Reservoir in Central China (Hubei Province). The species is morphologically similar to A. sagittatus, but it differed conspicuously in sequences of three molecular markers. Ribosomal internal transcribed spacers 2 sequence identity of the new species was 94.7–95.5%, 91.8–92.7% and 80.0–83.9% with A. huronensis, A. tenuicollis and A. sagittatus, respectively. cytochrome c oxidase and NADH dehydrogenase subunit 3 sequence identity with these three species was lower than 92%. We conclude that this is a new tapeworm species, and we named it after the locality: Atractolytocestus danjiangkouensis n. sp.
