You can easily have a Jaguar in the 125 with a Texas and at least a Jack Dempsey.I know those two cichlids can for sure defend themselves against a Jaguar,but the Convict will be a trouble maker,cause the one I have in my 125,is a pain in the butt,with the texas,green terror,and severum.Not saying a Jaguar is a sissy,but I use to have one with my Oscar,but the Oscar and the Jaguar got into a major fight,where my Oscar beat the living crap out of the Jaguar,such a shame I had to remove the Jag too,such a smart cichlid.A Jaguar will choose its spot,I say if you had a cave for the Jaguar,it will come out when he or she feels more comfortable enough,to explore the tank.