State-Of-The-Art Qld Tech To Determine How Clownfish See

University Of Queensland Designed The Display Specifically To Measure How Clownfish Interact With Ultraviolet (UV) Light

State-Of-The-Art Qld Tech To Determine How Clownfish See
By Stuart Layt

Australian researchers have developed a special television-like display to show to fish in an attempt to better understand how they see the world. The team from the Queensland Brain Institute’s Marshall lab at the University of Queensland designed the display specifically to measure how clownfish interact with ultraviolet (UV) light. Dr Samuel Powell said many animals can see into the UV end of the spectrum beyond what humans can see, and they wanted to test how they interact with objects that give off UV light. “The test works a lot like the human colour blindness test, where people who are unable to see certain colours can’t see patterns on the test like numbers,” Dr Powell said.

“Our fish are trained to poke the UV dots that display and get a food reward, but they only get it when they accurately poke the right dot.” Of 416 trials, 360 saw the fish correctly peck the UV target. Dr Powell said they can then measure exactly what wavelengths the fish can see, which gives them an idea about what they use that vision for in the wild. “There seems to be indications, and we’re still researching this, that their white stripes can be more and less reflective of UV light,” he said. “That seems to be something to do with dominance signalling, so that’s what we’re looking into with them.” The researchers came up with the relatively simple experiment design almost out of necessity, needing a simple way to measure UV interaction that could be immersed in a fish tank.

They used commercially available UV-emitting LEDs, which are more commonly used at the dentist to harden dental resin. Although Dr Powell said it was unlikely the tech would make the jump to human televisions any time soon. “You’d have to wear sunglasses and sunscreen while watching it, and the resolution is quite low – eight by 12 pixels in a four- by five-centimetre area – so don’t expect to be watching Netflix in ultraviolet anytime soon,” he said. Dr Karen Cheney said the technology will now allow researchers to expand their knowledge about a range of animals which are known or suspected to see UV light. “Bees use UV patterns on flowers to locate nectar, for example, and fish can recognise individuals using UV facial patterns,” she said. “This technology is allowing us to understand how animals see the world, helping answer significant questions about animal behaviour.”

This news was originally published at Brisbane Times