During chase scenes, movie protagonists often make their getaway by releasing a decoy to cover their escape or distract their pursuer. But this tactic isn’t reserved for action heroes. Some deep-sea animals also evade their predators by releasing decoys – glowing ones.
Karen Osborn from the Scripps Institute of Oceanography has discovered seven new species of closely related marine worms (annelids) that use this trick. Four of these pack up to four pairs of “bombs” near their heads – simple, fluid-filled globes that the worms can detach at will. When released, the “bombs” give off an intense light that lasts for several seconds.
The worms were collected from the Pacific Ocean by remote-controlled submarines. Unfortunately, the small size of the bombs and the low resolution of the sub’s cameras meant that Osborn was never able to film the worms actually releasing their glowing payload in their natural environment (although she did capture some great videos; see bottom of post).
Nonetheless, the specimens she recovered would indeed launch one or two bombs, when they were prodded on any part of their body. If she prodded them further, they would release more bombs, until they ran out. The fact that some worms also carried much smaller globes suggests that they can regenerate them once their supply is exhausted.