20 March 2008

University of Queensland research has identified a completely new type of vision never seen before in the animal world – and it is probably all about sex.

Professor Justin Marshall, from UQ’s School of Biomedical Sciences and the Queensland Brain Institute, has found the common mantis shrimp sees light in a way that is vastly different to other animals, including us humans.

“We are sensitive to light intensity and colour, but we need cameras and filters to allow us to see different types of light,” Professor Marshall said.

“To find out these animals can see circular polarised light, it is as if we had discovered colour vision for the first time – it is quite a breakthrough.”

What puzzled Professor Marshall after discovering this unique talent in the mantis shrimp, was what it was used for?

“It really is bizarre why these animals even bother with this type of vision,” he said.

“But after doing a number of tests over the years looking at the physiology and behaviour of mantis shrimps, we have come to the conclusion it is used for sex.

“Only the males have this ability, implying it has something to do with sex.

“It is probably some secret communication channel between males and females while at the same time preventing predators from knowing what was going on.”

He said the mantis shrimp was an amazing animal to study as it has a very small brain but one of the world’s most complex visual systems.

“Us humans only have three colour channels,” he said.

“These little guys have 12, and can see both linear and circular polarized light – it is remarkable.”

He said humans could see the effect of linear polarisation through things such as polarised sunglasses, which cut out glare for driving and boating.

Circular polarisation is also used by humans in things such as 3D glasses for movies, filters for cameras and medical imaging systems to detect skin cancer.

“It’s quite amazing to think how much circular polarisation technology we have, and that 400 million years ago nature got there first with a mantis shrimp’s eyes,” he said.

The research is published in the current edition of scientific journal Current Biology.

Media: Professor Justin Marshall (07 3365 1397; 0423 024162international +61 7 3365 1397) or Andrew Dunne at UQ Communications (07 3365 2802, 0433 364 181; international +61 7 3365 2002, +61 433 364 181). Hi-res images are available of Professor Marshall and the mantis shrimp are available by contacting UQ photo librarian Diana Lilley (07 3365 2753; international +61 7 3365 2753 or email d.lilley@uq.edu.au).