I’ve read about this before. It’s a parasite. From what I remember they can live fine with it. I used to see it in a lot of ghost shrimp that I fed my seahorses
I can’t find the paper I read about it online now. I thought it was from UF but I may be wrong. They mentioned trying to remove them but that the shrimp faired better with them being left alone and they were not an issue for infecting fish.