Vision of cuttlefish offers surprises

BRISTOL, England, Feb. 20 (UPI) -- Cuttlefish have the most acute polarization vision yet found in any animal, British researchers say, giving them a covert communications channel.

Scientists at the University of Bristol and Australian colleagues say cuttlefish and their colorblind cousins, squid and octopus, see aspects of light -- including polarized light -- that are invisible to humans.

"Just like color and intensity, polarization is an aspect of light that can provide animals with information about the world around them," Bristol researcher Shelby Temple said. "If you've ever put on a pair of polarized sunglasses glasses to cut the glare from water or the road, or gone to a recent 3D movie, then you've observed some aspects of polarized light."

The researchers, writing in the journal Current Biology, say they found cuttlefish were much more sensitive to polarization than previously thought.

They modeled how underwater scenes might look to an animal with high-resolution polarization vision and found there is much more information available in the polarization dimension than had been thought.

"These extraordinary findings suggest that we need to re-examine how we have been measuring the visual world underwater," study co-author Justin Marshal of The University of Queensland said.

"Cuttlefish may be using the polarization of light much like we use color, which means we may need to look at camouflage and communication underwater in a whole new way."