New research eyes off colourful reef fish

February 11, 2010
Close up of a trigger fish's eye

(PhysOrg.com) -- Most people wouldn't give a second thought to the inner workings of the fish eye. But research by University of Queensland scientists is unlocking the secrets hidden behind these fishy lenses.

Professor Justin Marshall, and colleagues from the Sensory Neurobiology Group within UQ's Queensland Brain Institute, have found, for the first time, how certain types of fish see colour.

Professor Marshall's work revolves around the role double cones play in the vision of trigger fishes.

Cones are light sensitive cells in eyes that allow us to see, and double cones are two such cells fused together.

“It has been suggested that double cones are used for achromatic (non-colour) tasks such as luminance, motion and polarization vision,” Professor Marshall said.

“This is the first direct evidence that individual members of double cones are used in colour vision as independent spectral channels.”

“This is odd as they are the commonest photoreceptor in the eyes of most diurnal animals and these new results show for the first time that in the trigger fish, a colourful inhabitant of The , these cones are used for colour vision.”

He said while the eyes of most vertebrates including , frogs, reptiles and kangaroos, are packed with double cones, their function was not previously known.

“These photoreceptors are not present in human retina or other and, perhaps as a result, we have overlooked the fact that we do not know what they do,” he said.

“The discovery that use double cones for colour vision solves a centuries old mystery.”

The research, which was a collaboration between UQ researchers and Dr Misha Vorobyev, from the University of Auckland, was published recently in scientific journal Biology Letters.

Explore further: Behavioural tests probe ray and shark colour vision

Related Stories

Fruit Bats are not 'Blind as a Bat'

June 12, 2007

The retinas of most mammals contain two types of photoreceptor cells, the cones for daylight vision and colour vision, and the more sensitive rods for night vision. Nocturnal bats were traditionally believed to possess only ...

Human vision inadequate for research on bird vision

May 12, 2008

The most attractive male birds attract more females and as a result are most successful in terms of reproduction. This is the starting point of many studies looking for factors that influence sexual selection in birds. However, ...

There is more to bats' vision than meets the eye

July 28, 2009

The eyes of nocturnal bats possess two spectral cone photoreceptor types for daylight and colour vision. Reporting in the open-access, peer-reviewed journal PLoS ONE, scientists at the Max Planck Institute for Brain Research ...

Recommended for you

Genomes uncover life's early history

August 24, 2015

A University of Manchester scientist is part of a team which has carried out one of the biggest ever analyses of genomes on life of all forms.

Rare nautilus sighted for the first time in three decades

August 25, 2015

In early August, biologist Peter Ward returned from the South Pacific with news that he encountered an old friend, one he hadn't seen in over three decades. The University of Washington professor had seen what he considers ...

Why a mutant rice called Big Grain1 yields such big grains

August 24, 2015

(Phys.org)—Rice is one of the most important staple crops grown by humans—very possibly the most important in history. With 4.3 billion inhabitants, Asia is home to 60 percent of the world's population, so it's unsurprising ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Drake411
not rated yet Feb 12, 2010
The article neglected to say what that first direct evidence was. How do we know double cones are for color?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.