What is this blue-green bioluminescent jellyfish I saw at Aquarium of the Pacific?
That is a Jellyfish! :D

Someone else took a picture of that same Jellyfish:

http://www.yelp.com/biz_photos/aquarium-of-the-pacific-long-beach?select=36BuiiqeN7OIFbowSDkPcw

Here is a picture from an article about the exhibit's jelly fish:



Source: New Jellies Exhibit at Aquarium of the Pacific Explores the Mysterious Lives of These Gelatinous Sea Creatures