Intra-host competition between co-infecting digeneans within a bivalve second intermediate host: Dominance by priority-effect or taking advantage of others?

► Acanthoparyphium sp. and Curtuteria australis have different encystment sites within the cockle host, with the latter showing a much stronger preference for the foot tip. ► Curtuteria australis has higher overall infection success than Acanthoparyphium. ► Infection success of C. australis was unaffected by co-occurrence with Acanthoparyphium. ► Prior or simultaneous exposure of the cockle to C. australis cercariae results in reduced infection success of Acanthoparyphium cercariae. ► Overall, C. australis is the stronger competitor while Acanthoparyphium is less exposed to non-host predators due to its preferred encystment site.