Suncub,
Comb jellies are bioluminescene creatures and actually are not jelly fish but tiny plankton animals.
Their light is activated with water movement , try moving the water around them and watch. Lots of these guys on our night dives.
http://www.google.com.bz/search?q=c...ent=firefox-a&rlz=1R1GGLL_en___BZ366

White Sands Dive Shop
https://whitesandsdiveshop.com/