Nevr seen that before either. It looks like a blodworm to me though. We get the rice looking ones and these little black balls also that gross me out. If I find one, it grosses me out and I have to throw every fish out. I just can't eat them. But we get seal worms in saltwater fish. I can just pick those out and move along. They don't bother me at all.
I was at an ice fishing derby a couple of winters ago and I was getting my perch measured for the "perch pot". One of the guys who was watching commented on what a great meal they were going to make. I offered them to him, and he asked why I didn't want them, he assured me they were delicious. I told him I wouldn't eat anything from that lake because the fish were full of worms. You could even see them through the skin. He wouldn't believe me that they were worms so I pulled out my knife and started filleting right there, pulling out worms and letting them wriggle on the table. That guy, along with a few onlookers didn't seem too eager to take those perch off my hands anymore, filleted and all.
