Shipping fish in boxes typically involves a considerable investment in money, time and effort, so the materials used should be the best available.
Packaging materials should be watertight, should prevent rapid changes in temperature, and should be rugged enough to withstand handling during shipping. A plastic bag is the watertight component. It is nestled in an insulated box that protects fish from rapid temperature change.
The insulated box is then placed in a sturdy outer box for protection.
Bags:
Fish bags are made of transparent polyethylene plastic and should be at least 3 mil thick to withstand some abuse without leaking. Many experienced commercial shippers opt for a more expensive 4-mil plastic bag.
Common “pillow slip” bags have a single bottom seal that creates sharp corners when filled with water. Small fish can sometimes become trapped in these corners during shipment and die. You can “square up” the corners by folding them up and taping them to the side of the bag.
Some bags have square bottoms so that they sit flat on the bottom of the box. Square-bottom bags are more expensive but have become standard in the industry because they do not trap fish in the corners and use the space in the box more fully.
Bags are available in many sizes. Some are small enough to ship individual male betas. There are bag sizes designed to fit snugly in standard size shipping boxes (e.g., full bags, half bags and quarter bags). Bags are available from several Internet sources if there is no retail outlet near you.
Even sturdy, 4-mil bags can be punctured during shipment, so many shippers double- or even triple-bag their fish to ensure that at least one bag will remain watertight. This is a good practice when shipping fish with sharp spines.
Once the bags are filled with water and oxygen (or air), they need to be sealed. While you can simply twist and tie an overhand knot, the method most commonly used is rubber bands. The top of the bag is twisted and then doubled over and the rubber band wrapped tightly around the resulting loop.
If rubber bands are used, they should be of a good quality that will not break when significantly stretched. Operations that ship large volumes often speed up packaging by using mechanical clamping machines that crimp a small metal clamp around the bags.
Insulated boxes:
Fish boxes are typically insulated to keep the temperature relatively constant during transport. Most are made from polystyrene Styrofoam that is approximately 0.75 to 1 inch (1.8 to 2.5 cm) thick.
Boxes are available in standardized sizes made specifically for transporting fish. They are usually small enough for an individual to easily grip and lift during the handling process. They are available from several Internet sources.
A Styrofoam insulated box protects the outer box from leaks, whereas Styrofoam panels will not. Other types of insulation that can be used include inflated “quilted” materials, other rigid insulation panels cut to size, and even newspaper. However, most of these materials are inferior to a Styrofoam box in insulation value.
Outer shipping box:
While Styrofoam is watertight and provides good insulation, it is not a rugged material and can be easily punctured, chipped or broken during the shipment. So the insulated box must be placed in a rugged outer container.
Usually this is a corrugated cardboard box that will protect the Styrofoam or other insulation from damage. Like bags and Styrofoam boxes, outer cardboard boxes specifically designed for shipping fish are available from several Internet sources.
The inner, insulated box should fit snuggly inside the outer box to give the best protection possible. A good quality packing tape should be used to seal the outer box.
Authors:
Craig Watson, Kathy Heym Kilgore and Carlos Martinez
