Swima bombiviridis

Swima bombiviridis, the green bomber worm, is a free-swimming deep-sea annelid in the family Acrocirridae. It was first recorded off Monterey Bay, California, and was announced in 2009 by researchers at the Scripps Institution of Oceanography together with several other new species of its clade. The worm has a transparent body, can grow beyond 30 millimeters in length, and swims with bristled parapodia. Its best-known trait is a set of modified gills that it can drop when disturbed: small spheres about a millimeter long that glow green for several seconds. They are thought to distract predators rather than serve in reproduction, because juveniles and adults both have them. The species is holopelagic, spending its whole life in the water column, and has been recorded at depths of up to 3,600 meters. Groups of hundreds have been seen, but the remoteness of the habitat makes study difficult.