The gill curl doesnt look that bad but cannot be cured. It has to be cut off under sedation by a vet. Usually due to poor water quality/tank size. I’d imagine it could be from bad genes and from captive breeding as well.
Would just just watch if it’s not bothering fish and can’t get it to a vet. Don’t want to do it urself unless you have to.
If u’r determined to do it urself then clove oil 0.5ml per gallon. Slowly add and check the response and add more as needed. There’s a video on YouTube that shows what it should look like and how it’s done.