Piranha with gill curl I know Arowanas get this. I have bought a rare piranha. (Pygocentrus piraya) And it has gill curl. I know it is not from me. The fish was 2 inches in size when I gotten him, So I did not notice the gill curl in time. It is pretty advanced now being that 1/3rd of the hard part is affected. What surgical procedure do you recommend? If I cut all of it off it will show a good deal of his gills. Or do I make relief cuts in the gill toward the head? Or a little of both? <Actually, neither of these. I would leave this animal as is. "Gill curling" is almost always either a manifestation of genetic disposition or a developmental anomaly. The last due to "poor water conditions", lack of dissolved oxygen, nutritional deficiency... Not "correctable", and likely more dangerous to cut the existing structure in hopes that it will regenerate "properly" than the possibility of damaging, killing the specimen> As him being a piranha. A feisty one at that. What tranqs are easy for a hobbyist to obtain? <tranqs?> I have never done any surgery. So if you could give me a step by step instructions that would be great. Thank you very much. <Bob Fenner who would "live" with the curled gill cover.>