Thanks, I'm glad you like it.
Pretty basic camera stuff. A point-and-shoot camera (Canon G-15) in a housing (Ikelite); with a yellow filter for this nighttime bioflourescence. The light source I was using in 2015 for video was a dark blue "head" on a small Gobe light, and dark blue dichroic filters on two Ikelite DS-161 strobes (which have a video LED mode, but it isn't a lot of lumens even before the filter)
Some of it was pure luck; there aren't any available "manual" settings for video with a G-15 so I got whatever settings the camera uses in HD video. This LOB trip in Belize was the first time I was trying bioflourescence at night underwater, and this sequence where the crab-on-the-sponge was first lit up by "regular lighting" [with a yellow cast in the video because of my yellow filter] and then lit only/mostly by the deep blue light was pure dumb luck. Oh, and the big sea crab that happened to light up is pure luck too. I have since illuminated other sea crabs at night underwater with little effect, so which critters bioflouresce is, at this point for me at least, totally unpredictable.
Youtube improved the video by stablizing some slight jerkiness.