However, I was distracted from the action because the tank contained not box jellyfish, but moon jellyfish, a jelly which I find to be sweet natured. I realize this makes me a supernerd.
The two have very different demeanors and don't look that much alike.
Box Jellyfish via The StashBox
Moon Jellies via Saatchi Gallery
I've swam through a tide of moon jellies with nary a sting.
However, box jellyfish will kill the F out of you.