The clusterwink snail has been found to use its shell to scatter its bright-green bioluminescence in all directions, possibly as a means of making itself look bigger to ward off predators. Researchers at Scripps Institution of Oceanography conducted experiments on the snails, also known as Hinea brasiliana, and documented how they started to glow when confronted by a threatening animal, such as a crab or a shrimp. The scientists noted that the sudden production of light by the snails was like a burglar alarm going off. They also pointed out that bottom-dwelling snails rarely produce bioluminescence and that it was impressive that their shells so efficiently maximize the light signals. Even more impressive is that they can do so with shells of an opacity that would seem designed to stifle light transmission, not promote it. But when the snails’ bodies produce their green bioluminescence, the shell efficiently disperses only that particular wavelength. The researchers hope to apply their findings to the optics and bioengineering R&D industries. The next step is to determine how the shells function the way they do and how that knowledge can be used to build materials with improved optical performance. The work was described in the Dec. 15, 2010, online version of Proceedings of the Royal Society B (Biological Sciences).