Diphyllidea is a monotypic order of Cestoda (tapeworms). Members of this order are gut parasites of elasmobranch fishes including rays and sharks. Disphyllidea infect their hostâÂÂs spiral intestine. Scolex is the type of tapeworm associated with Disphyllidea, which have a hook-like structure that helps attach to their hostâÂÂs gut.