Is it possible that my Gold Gourami, Nugget, is lonely? I had him in a 40 gallon tank with a small school of Serpae tetras, a couple cories, and a pleco. I'm going to college in the fall, and my mom is going to be taking care of that tank for me until I get back. So to make it as easy for her as possible, I sold all the fish except Nugget to my LFS. Now he's alone in the tank, and his activity has changed drastically. He barely comes out of his cave except to eat or get air at the surface. He's very timid, hiding from me every time I approach the tank. Is he stressed because he doesn't have other fish sharing the tank with him any more?