Cassiopea Xamachana - Upside Down Jellyfish 

The Upside Down Jellyfish, also called the Cassiopeia Jellyfish, is so named because its flattened bell (head) rests on the bottom. It extends its frilly tentacles up into the water column where they capture planktonic food and absorb light that is used by photosynthetic algae that are housed in its body.

It also prefers a wide sandy bottom to the aquarium and requires high intensity light for photosynthesis to occur. It will not tolerate copper or high nitrates in the water, and since its body is composed of 95 to 98% water, sudden changes in salinity or pH can have radical consequences.

Its sting is mildly toxic; humans very rarely notice the sting. Care should still be taken though when handling it or while doing maintenance on the aquarium.

It will require daily supplemental feeding with zooplankton substitutes.