Humm... I am still not seeing these guys as suitable for a 1gal, personlally I don't think any crab is suitable for a 1gal, but maybe that's just me... Also, it doesn't specifically say what water these guys prefer, but I am thinking they would benifit from at least brackish conditions, if not full SW. (comming from ocen shores in flordia, and it plainly says the eggs they lay drift out into the ocean).
You have drawn my intrest into them though, I think it would be neat to have a couple of these guys in a large vivarium/biotope type tank with some anoles or something.