Crystal Jellyfish

About

The crystal jellyfish (Aequorea victoria) is one of the most scientifically significant animals ever kept in an aquarium, and also one of the most demanding. Native to the open waters along the Pacific coast of North America, it drifts through the water column feeding on small zooplankton and other soft-bodied invertebrates, including smaller jellyfish. In the wild it appears largely transparent, but under ultraviolet light the bell's edge glows a soft blue-green. The result of a photoprotein called aequorin and a fluorescent protein that later became the basis for GFP, a tool that transformed modern biology and earned its discoverers a Nobel Prize in 2008. In captivity, keeping this species alive requires a specialized kreisel tank, a circular flow system designed to keep jellies suspended without letting them get drawn into pumps or corner intakes. They absolutely cannot be mixed with fish or most other invertebrates. Even experienced marine keepers find jellies a genuine challenge, and this species is firmly in expert territory. Their lifespan is short regardless of husbandry, so the commitment here is less about years and more about providing the right environment for a truly otherworldly animal.