Some jellyfish have long tentacles with powerful stinging cells to catch fish for food, but this one appears to feed in a different way. It probably has microscopic algae living in the jelly mass, just like tropical corals have tiny algae living in their tissues. The algae photosynthesise just like plants on land, and produce various sugars which the corals, or in this case jellyfish, can use as food.

So the jellyfish carries its own "supermarket" with it wherever it goes! Rather clever really. And they never need to try to eat - it is all automatic! As long as the jellyfish keeps pulsing the bell and swimming to stay close to the surface where there is plenty of light for the algae, everything ticks along nicely thankyou.