A device for the transport, introduction, and acclimation of fish. The device, a bag comprising a window of 
dialysis membrane, allows fish to be transported within the bag and acclimated to new 
saline environments by allowing solutes, mainly salt and 
hydrogen ions, to slowly equilibrate between water within the bag and water in the source environment so as to avoid shock to the fish. Although the majority of the bag is impermeable to solutes, the 
dialysis membrane window is not, and is 
size dependent based on the characteristics of the fish to be acclimated. In use, the fish is placed in the bag along with 
source water from the source of the 
organism. The bag is then immersed in the destination aquarium, and passive 
diffusion allows the slow transport of solutes across the semi-permeable 
dialysis membrane, slowly equalizing the water parameters inside and outside the bag. After an appropriate amount of time has passed, the occupants of the container are removed and placed in the new environment.