of Erenna, a deep-sea relative of the jellyfish, is a rarity. Indeed, received wisdom holds that most deep-sea animals cannot detect red light. But researchers recently found this as-yet-unnamed species of the genus Erenna off the coast of California. Although many such jellies use bioluminescence for self-defense, flashing furiously when disturbed, this creature appears to employ its scarlet light to lure prey. The glow is highly localized, tipping the animal's tentacles such that when the tentacles are flicked to and fro, they resemble the copepods that Erenna's prey feed on. The discovery is detailed in the current issue of Science.