I've always thought hooks prevented fish from eating and that there was nothing they can do about it. But after reading this, I remember way back when I had like 3 Koi ponds with Kois the size of my legs. When I hand fed them, and swam with them, they would "suck in" my fingers and toes, but when there was a leaf that accidentally got sucked in, they would blow it out with enough force. I don't know if all fish (except sharks or whales) can do this. But if the Pikes this study used are like Kois, then it makes sense how they're able to get rid of the hook. They probably just keep moving their mouth while sucking in and when they feel there's a loose object inside their mouth that they don't like, they blow it out.