I'm at work right now, but I will take a look in my book when I get home tonight, and see if it has an answer for you. My yellow clown gobi is extremely peaceful, but I can't tell you how they will treat another of thier own species in a tank that small.
Also, you may want to be careful of the Bio-load on your 5 gal. I have only 2 fish in a 10 gal.