Predators
Aurelia aurita is known to be eaten by a wide variety of predators including the Ocean Sunfish (Mola mola), the Leatherback Sea Turtle (Dermochelys coriacea), the scyphomedusa Phacellophora camtschatica, and a very large hydromedusa (Aequorea victoria). Moon jellies are also fed upon by sea birds, which may be more interested in the amphipods and other small arthropods that frequent the bells of Aurelia, but in any case, birds do some substantial amount of damage to these jellyfish that often are found just at the surface of bays.
Aurelia jellyfish naturally die after living and reproducing for several months. It is probably rare for these moon jellies to live more than about six months in the wild, although specimens cared for in public aquarium exhibits typically live several to many years. In the wild, the warm water at the end of summer combines with exhaustive daily reproduction and lower natural levels of food for tissue repair, leaving these jellyfish more susceptible to bacterial and other disease problems that likely lead to the demise of most individuals. Such problems are responsible for the demise of many smaller species of jellyfish. In 1997, Arai summarized that seasonal reproduction leaves the gonads open to infection and degradation.
Some metazoan parasites attack Aurelia aurita, as well as most other species of jellyfish.
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