If you look at Roy's list, you wil find a section for Gonodactylaceus ternatensis. It is easy to sex them. Females have yellow antennal scales, males blue. Both will have the tell tale red intersegmental lines and orange meral spots. At two inches, this animal could easily live in a 10 gal. Granted it will eventually outgrow it, but that is a couple of years down the line and given the success that most people have with G.t, it probably won't live that long. G.t is a live coral specialist, In the field they usually live in the center of a branching coral head like Pocillopora damicornis. They chip away branches to form a central cavitywith one or two entrances. It might be interesting to get a grapefruit sized coloney and see if the G.t will set up residence. This is something I've been wanting to do for some time and haven't gotten around to it.
Once the animal reaches about 4 inches, I would definitely get it into something larger than a 10 gal system.
Roy