IMo,
if the tank is as i suspect a 4x2x2, then no, i would keep a single jaguar,
if it has different dimention, than mabey, i belive that becuase jags are known for there aggresive tendecy's (not always) that you will want at least a 6 foot long tank with tankmates, a pair would be streching a 120 if 4x2x4, and i think that a large male jaguar would fill out a 120 perfectlly, if you really do want to try tankmates, then get a nother large cichlid, like an oscar as stated above, as long as it is not another fish from the Parachromis speices.