1-3 inches in bell diameter. Upside Down Jellyfish are known for living their lives upside down, peacefully farming algae in their tentacles. They use this algae (which gives them their golden-tan color) to provide food for themselves. These jellyfish are found all throughout the world, in tropical, shallow lagoons. Our particular species, Cassiopeia xamachana, is from the Florida Keys and Caribbean.
Upside Down Jellyfish actually don't prefer your traditional jellyfish tanks. They enjoy tanks with wide, flat bottoms, where they can sit. A ten gallon aquarium with a divider between the filter and the jellies is typically enough to keep them happy.
Because they have a symbiotic relationship with zooxanthellae algae, it's best to provide them with strong lighting, although unnecessary. Upside Down Jellyfish that are not well lit will eventually revert to their natural blue coloration. Despite the fact that the algae provides food, Upside Down Jellies will still require feeding.
Upside Down Jellyfish do have some noticeable sting. It can cause minor irritation and itching. Exercise caution when handling your jellies.