A Hawaiian squid is shining new light on optical nanotechnology: the creature has a built-in flashlight made up of a previously unknown type of protein. The discovery, described in a report published today in the journal Science, could help researchers design novel nanoreflectors.

Wendy J. Crookes of the University of Hawaii-Manoa and her colleagues studied the three-inch-long squid Euprymna scolopes, commonly called the Hawaiian bobtail squid. The animal has a light-producing organ on its underside that helps it feed in dark waters and may help provide camouflage from predators. Glowing bacteria provide the light source, which is surrounded by stacks of reflective plates. But unlike previously studied reflective plates in other aquatic animalsthe majority of which are made up of crystals of a chemical known as purine--the squids reflective tissue is protein-based. The group of proteins, dubbed reflectins by the authors, has an unusual amino acid composition. The team notes that the reflectins are "a marked example of natural nanofabrication of photonic structures" and should inspire bottom-up synthesis of new spectroscopic and optic devices.