This video from the USA says about itself:
An unusual sighting of five Swima bombiviridis worms swimming in formation in Astoria Canyon off Oregon at 2,243 meters depth. According to the scientists, this is possibly a mating swarm. The glistening of the bristles is the result of scattering the bright lights of the remotely operated vehicle used to observe and collect these delicate animals.
Sea Creature Releases Glowing Decoy ‘Bombs’
By Clara Moskowitz, LiveScience Staff Writer
posted: 20 August 2009 02:08 pm ET
A newly discovered species of deep sea worm releases tiny balloon-like structures that glow in the dark to distract predators, scientists have found.
Researchers using undersea robots pulled up seven new segmented worm species belonging to a whole group of critters never seen before. Five of these species appear to cast off glowing bombs intended to throw off fish on the lookout for dinner.
“It was very exciting to see them and realize that they were very different from species we’ve seen before,” said lead researcher Karen Osborn of the Scripps Institution of Oceanography in La Jolla, Calif. “We think they’re using the little bombs as decoys to escape predators.”
Liberating part of one’s body as an escape tactic is rare, but not unheard of, Osborn said. Some squid and brittle stars (which are similar to star fish) have been known to cast off an arm to avoid being eaten.
In this case, the balloon bombs seem to be made of modified gill parts, and only glow once they are ejected from the worms, apparently to distract predators’ attention.
Glowing in the dark
The scientists dubbed the new group Swima bombiviridis (“Swima” meaning that they are good swimmers, and “bombiviridis” translating to “green bomber” in Latin). They announced the finding in the Aug. 20 issue of the journal Science.
See also here.