Fish are generally shipped bagged with water and oxygen (not air, but pure oxygen). For puffers it's a good idea to have three fish bags lined together so if one layer gets a poked hole, there'll still be two layers keeping the water in. The bags are then placed in a styro box. Need to make sure the bag cannot roll around in the box. A trick to this is filling empty fish bags with just air and surround the bags with the fish. Also for puffers...they should be bagged individually. Keep shipping cost in mind. More water means more weight, but you need enough water to cover the animal's dorsal fin. The oxygen is most important. In a bag with just air, survival time is only a couple hours. In a bag with pure oxygen, the animal would probably die of ammonia poisoning before running out of oxygen. The oxygen will last for days. Maybe your LFS
can give you appropriate sized bags and if they have an oxygen tank, they can pack them for you
It's not hard to do, so when you're ready, let us know and we'll help you out.
We, as a people, know so much more about outer space than we do about our own oceans. This lack of knowledge can very well spell the dangers that lay in wait for us.
The oceans surely would swallow us before a rock comes down to smite the planet of it's life.