I've seen this picture for a couple of years. Everyone has different opinions but the most often the opinion people had was that it was a bad case of gill curl. I don't know what it is but it's freaky. Anytime you Google any disease about aros, this picture would show up. I wonder, can it be photo-shopped. The fish looks healthy and with a healthy body so can an aro look so healthy with a big growth in its gills?