No zip-locks! They are certain to fail! Many auctions don't allow them as they so often pop open. In the mail it is certain to happen.
It will take some type of plastic bag that can be tied shut. For bags that are not breather bags add just enough water to let the fish swim easy. They don't need water as much as air. O2 is best but not for the one time shipper. Grip the bag so as much air is trapped as possible, twist the bag top and wrap a rubber band around the twist, fold it over and seal with rubber band again. Stick this bag inside a second bag upside down and seal the second like the first. This gives more protection but the main value is in the way the bag corners are rounded when double bagged. In single bags there are pockets in the corners and fish get in them and die. Pack the bags in a box with lots of insulation. Pad them well to protect from heat and cold as well as cushion them . They WILL be thrown across the room so prep for that. They will likely arrive will box corners smashed and tears in the outside box. Don't leave the plastic bag next to the sides so it gets torn.
That's a primer on bagging but it takes more for the full trip.
Last edited by PlantedRich; 11-05-2012 at 02:32 PM..