Fishy research confirms archerfish seeing clearer

Apr 15, 2010
An image of archerfish preying on insects above the surface.

(PhysOrg.com) -- If you have ever looked up from the depths of the ocean, you will understand how difficult it can be to identify objects above the surface.

Now University of Queensland scientists at the Queensland Brain Institute and School of Biomedical Sciences have identified a that can clearly visualise both the water and air mediums simultaneously.

Archerfish live in and rivers. Their unique vision not only allows them to see above and below the but also to easily distinguish shades of brown in the depths of the water, detect dark objects against the bright blue sky and to recognise tiny colourful objects from great distances against a backdrop of green foliage.

“Archerfish spit jets of water with remarkable accuracy at insects as much as a meter or more above the water's surface, despite the distortion that occurs due to the bending of light as it passes from air to water. They do all this while being attentive to potential predators approaching from above or below” said lead investigator Dr Shelby Temple.

Already the research, published in : Biological Sciences and featured in the latest edition of Nature, has far-reaching impacts.

Dr Temple said the findings provided the first empirical evidence for a functional role for differences in across the eye - a phenomenon found in most vertebrate taxa such as humans, mice, pigeons, chameleons, bullfrogs and some fish. However, to date, there is no explanation for why different parts of the eye might need to see colours differently.

“The correlation we found between the colour sensitivity of the archerfish eye for ‘looking' in different directions and the background environment in those different directions indicates that the archerfish eye is highly tuned to differences in the spectral quality of light in different directions,” he said.

“Our findings might help to solve why such intraretinal differences exist in so many other vertebrate eyes.”

Dr Temple's supervisor, Professor Justin Marshall, said it was fascinating to try and understand how other animals saw their world.

"As this story shows, when they have specific necessary tasks, animals often come up with remarkable adaptations to help them survive," Professor Marshall said.

“The innovation in design here is called ‘matched filtering' where the visual system takes into account the environment and, through evolution, adjusts its self to the outside world. Under , this world changes more rapidly from top to bottom than it does in air and archerfish have come up with a neat system of accounting for this change and retaining exquisitely tuned vision in every direction at once. This design principle is something we can learn from in our own attempts at engineering.”

Explore further: Male monkey filmed caring for dying mate (w/ Video)

Related Stories

New research eyes off colourful reef fish

Feb 11, 2010

(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. ...

Edge detection crucial to eyesight

Oct 07, 2009

(PhysOrg.com) -- In a major advance in understanding how our eyesight works, Australian scientists have shown that birds' amazing flight and landing precision relies on their ability to detect edges.

Bees see super color at super speed

Mar 17, 2010

(PhysOrg.com) -- Bees see the world almost five times faster than humans, according to new research from scientists at Queen Mary, University of London.

Recommended for you

Male monkey filmed caring for dying mate (w/ Video)

Apr 18, 2014

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Orchid named after UC Riverside researcher

Apr 17, 2014

One day about eight years ago, Katia Silvera, a postdoctoral scholar at the University of California, Riverside, and her father were on a field trip in a mountainous area in central Panama when they stumbled ...

In sex-reversed cave insects, females have the penises

Apr 17, 2014

Researchers reporting in the Cell Press journal Current Biology on April 17 have discovered little-known cave insects with rather novel sex lives. The Brazilian insects, which represent four distinct but re ...

Fear of the cuckoo mafia

Apr 17, 2014

If a restaurant owner fails to pay the protection money demanded of him, he can expect his premises to be trashed. Warnings like these are seldom required, however, as fear of the consequences is enough to ...

User comments : 0

More news stories

Biologists help solve fungi mysteries

(Phys.org) —A new genetic analysis revealing the previously unknown biodiversity and distribution of thousands of fungi in North America might also reveal a previously underappreciated contributor to climate ...