Tidepool Tim says,  “Moon jellies are an abundant seasonal phenomenon all along the Maine coast in early summer. They grow quickly, shed their spawn, and they are eaten by fish or just slowly disintegrate washing up on area beaches by the millions. The white rings that can be seen in a moon jelly are their gonads. their swimming action is very hypnotic and if one looks closely they can see a very fine fringe of tentacles around the bell of the jellyfish. We used to collect thousands of these jellies and preserve them for science supply companies. My kids and I would take the skiff out in the bay and dip up 200 or so into a pail, preserve them with formalin, and then seal the lids.  We'd do dozens of buckets each trip. It was good, clean family fishing fun!”