It's a little hard to tell since a lot of Sea Nettles at this stage all look very similar before they get any of the distinct markings that make them easy to tell apart, but based off MBA's usual species, I would guess this is a juvenile Purple Striped Jelly before they start to get the striping, I'm not 100% confident though since I know they've been exhibiting a lot of different species lately in the Drifter's Gallery that haven't been exhibited in a couple years
Actually, looking around some more on iNaturalist, the tentacle coloration matches most with either the Northern Sea Nettle (Chrysaora melanaster), or the Pacific Sea Nettles, though I wouldn't get why they'd be displaying juveniles when they already have the big tank full of adults, so I'm leaning more towards the C. melanaster. If true, then this would be the first time since what looks like 2013 they've exhibited them? Really awesome
