New Ottos, one looks different?

The "chest" stands out on both (the silvery rib-cage-looking area), but i think i can see what you mean in the first picture. On both sides right below the eyes there is a shiny bubbly-looking area. That otto is smaller than the other, maybe they will disappear or "grow in".

I've actually never owned any Otto, but my best guess would be to leave him for a few days (in case its just settling in, or stress maybe...). If he still doesn't look right, go back to the LFS where you bought it and check the others out. They should have at least a three day return policy in which I'm sure they wouldn't mind swapping a fish out instead of replacing it.

Do you have an established tank? A lot of fish stores don't know how to feed them and the fish are so stressed because of shipping and lack of food that a lot of them do die. I am lucky because mine have been piggys from day one and eat everything. They love zuchinni and mini pellets and even eat bottom feeder pellets.

here is a pic of a tummy that is nice and full.

Yeah we you buy them you should make sure that they look like the one above, nice and fat..so you know that they are healthy and can handle the stress and when you get them home acclimate them slowly...