I though that lateral line erosion was an early symptom of HITH yet I've noticed that many Discus and Angels display a distinct lateral line indentation. I have also noticed that this indentation is not prevelent in other cichlids. Because the indentation is not always noticeable on every discus/angel does it mean the ones who display this "marking" are more easily suseptable to HITH or this this just a trait that these two species sometimes possess?