H. carpintis have been reported as using caves and overhangs in the mud banks, but again aren't classified as true cave dwellers. My male carpintis which is the dom fish in the tank, uses a cave when darkness falls on the tank. I would suspect that this species demonstrates similar behavior in the wild. Part of their survival mechanism, not just dominant/subdominant behavior. No doubt that a lot of CA/SA fish would fall into this group. True cave fish? Not sure if the Rift Lake cichlids even fall into that category? Adult Amphilophus also spend a great deal of time in rock caves, when spawning, or not feeding, probably as much as some of the Rift Lake cichlids. I guess it depends how specific you are considering a cave fish.