yup its gill curl. been like that for a long time. just the 1 side. i even did an operation on him 2 years back. hes 8 years old now and doing fine. just going to leave it. he was my practice aro... he had to put up with my upkeeping of my water / learning about keeping fish etc. he was kept in a smaller 18 wide tank only for the first 3 years so he got the curl. aside from that, hes a happy aro! lol.
widebar is perfectly fine. his black bars are a bit messed up. love hate relationship with my super aggressive rtg aro. been about 5 years together and they still go at it all the time but never really any major damage. weird couple lol.