I've had them just as long as the other fish, though. The guppies were floating at the top. One of the gourami's was being eaten by the kuhli loaches, and I know they didn't kill it.
Also the fish died during the day, and the UD catfish hardly move in the daytime. Actually I don't even see them much at night lol, they mostly stay in the log.
Also, I only recently got the gourami's and they're very small, and there's only one left now...