I think the Knight goby is a brakish fish, and I knowmy other fish arent, but I have had the tank running now for a year and the only fish I lost was one Gourami, and some neons, but the neons were eaten by the Knight Goby.
I dont know much about keeping fish and I am going to post a picture of a fish the I dont really know what it is. But he is tricky to take pictures of, very camera shy.