These siphonophore clips were put together from a series of dives by remotely operated underwater vehicles at the Monterey Bay Aquarium Research Institute, with thanks to Steve Haddock. For more information on siphonophores, a group of deep-sea colonial animals, see siphonophores.org. I originally made the segment for the home page of the journal Current Biology when they published a Quick Guide on siphonophores.
This video shows three different species of siphonophore, filmed at depths of hundreds of meters off the coast of California. The first is Apolemia, which can reach more than 40 meters in length (yes, meters), making it one of the longest animals in the world. It is sitting motionless in the water with its tentacles retracted. The second is Erenna, which uses glowing lures to attract prey. The third is Chuniphyes moserae, a fast-swimming calycophoran siphonophore.