This looks bit different. Never seen these before on polys. Don’t look like a parasite. Have you betters the fish and looked at it? Does it scrape off?
Yah this is new for me as well. Should I try to scrape it?? The fish is behaving as normal. Still the most active bichir I have and eats the most. I’m confused as well.They look like they grew. Definetly not what I have on mine. I would separate if possible and keep water pristine.