Does anyone know what causes fish to catch this disease? The fish in question here is an A. hongsloi. Half of the fish's face turned black, the rest the fish lost most of its other colorations. It began swimming in circles or death rolls and subsequently died the following day. Is there an explanation I have seen the a few times over the years in Apistos and even jewel cichlids. The pictures aren't clear as I would like, but the fish was spinning a not really in the mood to co-operate.