14 DAY TRIAL // These efficient killers have not changed since the dinosaur era.
They present sophisticated sensory organs yet scientists believed sharks and their relatives, rays (which are nothing more than flattened sharks) are color-blind.
Now a team at University of Queensland has revealed that stingrays could be able to see in color while the blue-spotted maskray possesses all the anatomical traits necessary for color vision. "Seeing in color could help rays find mates, detect prey and avoid predators," said Susan Theiss, a Californian PhD student involved in the project.
Theiss is led in her research by UQ team of supervisors Dr Nathan Hart and Professor Shaun Collin and collaborator Professor Justin Marshall. Her research is made on shovelnose rays and reef sharks at UQ's Heron Island Research Station, off Gladstone. "The animals were being trained to associate a colored light with food and tested to see if they could discriminate between the training color and a light of different color", said Hart.
A fire has destroyed the Station and six months of research on Friday, March 30. The team hopes to repeat the experiments in the future, to test if the presence of color detecting cells is linked to a color information processing. "The blue spotted maskray was different to the bull ray that killed Crocodile Hunter Steve Irwin but it was likely that many rays had similar color vision", said Hart.
Hart is also testing the potential color vision of the sharks with his ARC QEII Fellowship. "Knowing more about ray and shark vision could eventually help in the design of wetsuits and surfboards to reduce attacks on divers, surfers and swimmers", said Hart. "The design of trawler nets could potentially be altered to reduce shark and ray catches", said Collin, a fish vision expert.
Theiss, who is currently investigating the sensory ability of the wobbegong sharks, is going to perform a DNA analysis on rays and sharks in order to detect a genetic base for this ability.