New Find in the Pacific: Worms With Glow Sticks

By HENRY FOUNTAIN

Scientists have discovered seven new species of deep-sea worms in the Pacific. The worms, members of a new genus, Swima, are up to about four inches long, eyeless and have paddlelike bristles that move rapidly, allowing them to swim forward or backward.

That’s all very interesting, but what makes the worms truly spectacular are the little green glow sticks that are found on five of the species. Attached to segments near the head, these tiny organs — more blobs than sticks, actually — can be released from the body, instantly producing a bright green bioluminescence that lasts for many seconds as the worms swim away. The researchers refer to the worms colloquially as green bombers and say the phenomenon may help them distract potential predators.

Using remotely operated submersibles, Karen J. Osborn of the Scripps Institution of Oceanography and colleagues from the Monterey Bay Aquarium Research Institute and other organizations found the worms at depths of about 6,000 to 12,500 feet off Mexico, California and Oregon and near the Philippines. Their report is published in the journal Science.

The researchers say the new species are more closely related to worms that live in seafloor sediments than to other swimming worms, so they represent an evolutionary adaptation as bottom-dwellers moved into the water column.

The worms seem to be fairly common at those great depths; a video camera on a submersible recorded five of one species, S. bombiviridis, swimming together at about 7,000 feet. The submersibles did not record a bomb release in the wild, but the researchers were able to stimulate the release of bombs in the laboratory by touching the worms. They suggest that predators, presumably fish, that similarly try to disturb the worms would be left with the small glowing blobs instead of the tasty meal they were hoping for.