I have a 55 gallon with two cons and two male JDs. I've only had them all for a couple months now but they all came from the same tank and all have been together for about 8 years. Initially there was no issues but now my smaller JD has been anti-social and has basically stayed in the same hiding spot for a week now. He doesn't come out at feeding time either. I'm getting concerned. I haven't noticed any white spots or torn fins. The other fish are doing well. Is this normal for a fish to go through phases? Any suggestions??