I'm sad that I just lost my longnose hawk after he put up a very valiant fight to survive.
As I mentioned in a previous post, I'd been having a hard time keeping fish alive. I purchased "Rufus" because he'd been at the lfs several weeks and therefore seemed to have good resistance to disease. He was the first fish in a long while who didn't seem to have trouble living in my tank after having lost several fish shortly after introducing them.
Then, a few weeks ago, the thermostat went out on my heater and the tank got up to 92 degrees before I realized what was going on. Rufus was still alive when I started bringing down the temp, but disappeared the next day. I was just about ready to take down the tank in frustration, even though I knew the last loss had been a freak accident.
He had been gone for a week when lo and behold, he came back! I was just elated and felt if he was going to put up such a fight, I'd go ahead and keep the tank and went out and purchased a new fish and some snails to replace the casualties of the heater failure. Unfortunately he wasn't quite right after his return and was only back a couple days before he disappeared again. I think he's gone for good this time, but I'm still keeping the tank.
As for your question about compatibility, my large cleaner shrimp did quit coming out as soon as I introduced Rufus, and eventually disappeared altogether. I don't know if Rufus got him or not. I didn't really have anything else in there that he would have bothered. I can tell you he showed a lot of personality, watching everything, turning his head, etc. and he was tough as nails until the end.