Unless he's acting sick, as long as you aren't housing him with anyone else, I probably wouldn't bother with the vet. Just keep an eye out for mites.
What I would do is wait for him to poo and then take in a fecal sample to a vet just to check for anything odd, since the other one in the tank with him looked sickly.

He probably won't eat for several days till he settles in though.