I have an aquarium with a JD, Midas, + Tiger Oscar. At first there was a JD + GT, but I moved the GT to a different tank when I introduced the TO. For a while it was just the JD (who at first was bigger than the TO) and the TO, but then the TO got 2x the size of the JD. And my tank still seemed a little lonely, so I just added a Midas about a week ago thinking that since it was a Midas it could fend for itself (it being about 2/3 the size of the TO). But for the first week the TO terrified my poor Midas into hiding into a single cave of my aquarium all the time and never eating. So yesterday I totally changed my decor around and now my Midas has claimed its territory and is able to fight off my TO when need be! :headbang2: