My comment was half in gentle jest, but you have really found a relevant example there - thanks for sharing. I guess I have a potential PhD project if I ever want to get into maritime biology: "The Dark Side of the Fish: How Crafty Parasites Outmaneuver High-Tech Pest Control"
https://en.wikipedia.org/wiki/Perissodus_microlepis
Depending on which type is more frequent the other is more successful because the prey is more cautions on the other side...
edit: spelling