All fish that are purchased in the aquarium trade are transported from another distant location, which means only one thing - they are mailed.
It is completely legal since the cost of starting cultivation facilities in every state and region solely for the purpose of supplying the local trade is highly impractical.
When you purchase a fish these days and you watch them bag it you will notice that they fill the bag with a little water and fill it the rest of the way with compressed oxygen. My memory is fickle sometimes and I can't remember exactly what the compound is, but it is essentially a highly concentrated oxygen content - maybe someone will chime in and fill in the blank for me!
This way the fish can survive a few days without worry that they will sufficate in their confined space. Fish are fed sparingly, no often, when they are awaiting transport for two reasons: 1) the cost of feeding so many fish is too high for the import/export companies to justify feeding more than once every few days, and 2) if the fish hasn't eaten much recently then they won't produce waste in their transport vessels which would contaminate the water and cause increased chances or arriving with disease.
When shipped they are generally placed into a box containing styrofoam liner which will help to insulate the contents and maintain a more stable temerature.
When you receive a new fish in the mail it is important to not just simply pour them into your tank. You need to first float the bag in the water for about 15 minutes so that the temperature can adjust. Then you open the bag and scoop a small cupful of the aquarium water into the bag to give the fish a breath of fresh air. This will also begin to adjust the water in the bag to match the ionic levels present in your aquarium. Wait 5-10 minutes and then repeat the process of scooping up aquarium water and place it into the bag. Repeat this step for a total of about 5 or 6 times, removing a cupful of water from the bag if it gets too full and discard it - try not to introduce water from the shipping container into your display tank as the dealers tanks where it came from could contain disease pathogens that you do not want in your tank. After allowing the new arrival about an hour to adjust to the temperature and the environment it is safe to place him into the system. A good way is to have someone hold a net over a bucket and pour the water in the bag through the net into the bucket catching the fish who you can then drop safely into your tank.
The best idea is to place all new arrivals into a seperate Quarantine tank where they can be observed for a week before introduction into the main display tank. This gives you time to make sure that the new arrival is eating properly, and free of disease before going into your main system. If they turn out to have a disease then it is better to treat them in a seperate tank rather than in your main display.
