The first moon jelly washed right up in one of the boat landings. I saw it and my jaw dropped. A second, and bigger one washed up about ten minutes later. Neither of them would fit into my five gallon bucket! I ended up getting them back to where we were staying in bags. We then put them in large plastic bins with extra water. The water was very cold that day, and their salinity was crazy. 1.018, which is very low. Moon Jellies are often seen out in the ocean, from my knowledge. This is the first time I have seen live Moon Jellies from the Atlantic Coast, in the wild, in years.
I managed to get these jellies home and settled. They now reside in a 44 gallon pentagonal corner tank. As you may know, jellyfish don't generally do well in faceted tanks or ones with edges. These guys are so massive that they don't seem to care! I'm glad, because I don't have any other tank for them right now. I measured them and one is 14 inches and the other 10 inches across the bell. There are some bigger jellies out there, but these are giant, for what I have dealt with.
They both look like female, because their oral arms are dotted with what look like planula. Moon jellyfish have their eggs fertilized, and then hold on to them until they develop into planula. Some other jellies do this, whereas some species let their eggs loose, to be fertilized in open water. The tank water is now full of these tiny specs (visible to the naked eye!). I took some and checked them out under. Y microscope. They definitely appear to be planula! There are tons of them too! I hope that they settle so I can have some polyps. I do have moon jelly polyps already, but I don't believe I have Atlantic Moon Jellyfish Polyps. This is good because I have a definite species, and origin.
This time of year is when Moon Jellies are in season. It appears that most of them show up pretty big though. I suppose late summer they will be smaller, but harder to find. Lion's Mane jellies are also making appearances, but I have seen none so far.