Two scientists at Scripps Institution of Oceanography at UC San Diego
have provided the first details about the mysterious flashes of dazzling
bioluminescent light produced by a little-known sea snail.
Dimitri Deheyn and Nerida Wilson of Scripps Oceanography (Wilson is now
at the Australian Museum in Sydney) studied a species of "clusterwink
snail," a small marine snail typically found in tight clusters or groups
at rocky shorelines. These snails were known to produce light, but the
researchers discovered that rather than emitting a focused beam of
light, the animal uses its shell to scatter and spread bright green
bioluminescent light in all directions.
The researchers say the luminous displays of Hinea brasiliana
could be a deterrent to ward off potential predators by using diffused
bioluminescent light to create an illusion of a larger animal.
In experiments conducted inside Scripps' Experimental Aquarium facility, Deheyn documented how H. brasiliana
set off its glow, which he likens to a burglar alarm going off, when
the snail was confronted by a threatening crab or a nearby swimming
Wilson collected the snails used in the study in Australia and collaborated with Deheyn to characterize the bioluminescence.
"It's rare for any bottom-dwelling snails to produce bioluminescence,"
Wilson said. "So its even more amazing that this snail has a shell that
maximizes the signal so efficiently."
Discovering how the snail spreads its light came as a surprise to the
researchers since this species of clusterwink features opaque, yellowish
shells that would seem to stifle light transmission. But in fact when
the snail produces green bioluminescence from its body, the shell acts
as a mechanism to specifically disperse only that particular color of
Deheyn says such adaptations are of keen interest in optics and bioengineering research and development industries.
"The light diffusion capacity we see with this snail is much greater
than comparative reference material," said Deheyn, of Scripps' Marine
Biology Research Division. "Our next focus is to understand what makes
the shell have this capacity and that could be important for building
materials with better optical performance."