Mine keeps to himself as well, but isn't shy. I've had my JD for almost a year and he's in the four to five inch range. He's not as aggressive as the others at feeding time, but isn't shy about coming out when I come near the tank. My polleni is the biggest fish I have and runs the show over my new worlds. But the polleni also darts for cover if I move close to the tank and its not feeding time. The dempsey seems to just take everything in stride. He doesn't fight much, but will back down the other fish when need be.
