No sunglasses required for fish supper

Fishermen are always looking for a tasty catch - but it is the fish that have a natural advantage when it comes to spotting dinner, according to new research from The University of Manchester.

In a paper published this month in the Biophysical Journal, Dr Nicholas Roberts reports how individual light sensitive cells within the retina of goldfish are able to detect polarised light.

It's believed this type of polarisation vision improves visual contrast and can help an animal catch its prey more easily.

Researchers say this latest research is important because it is the first direct experimental evidence of a polarisation detection mechanism in any normal vertebrate eye.

Dr Roberts says: "Vision is the primary sense of many animals and the way they see their world is of fundamental importance to understanding aspects of their behaviour.

"Numerous animals have amazing visual abilities, which allow them to see the world in very different ways. One such ability is polarisation vision.

"Just as fishermen wear Polaroid sunglasses to help improve contrast, many different animals - including fish - have evolved to do the very same thing without the need of sunglasses. It is a surprisingly common ability throughout the animal kingdom."

Journal Reference: Biophys J. 2007 Nov 1;93(9):3241-8.

Photo Credit:US National Oceanic and Atmospheric Administration