First thing i saw was a tiny red dot on one of my danios. Later he started getting thinner and the red dot looked like a open wound. Now 3days later in quaraintine tank the wound grew bigger and he started floating and doesnt eat. He breaths heavily too. Anyone knows what to do with this. I did water tests and all seems fine tanks cycled i had this fish for a couple months already the red dot started apearing after i fed frozen/thawed bloodworms maybe that could be the case.