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PostPosted: 20 Sep 2012, 00:09 
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Study says sharks (wobbies in this case) have excellent but likely monochrome vision, as they only have on cone (light receptor) in their eyes. Whereas are stingrays and backboned fish have colour vision.

http://theconversation.edu.au/red-alert-in-the-deep-blue-sharks-are-probably-colour-blind-9677

Makes that guys zebra stripe shark deterrent sticker somewhat more plausible....

I think I remember seeing other researchers looking at electric fields emitted by things like that shark shield and finding that some sharks, might of been port jackson's or wobbie's, were actually attracted by them.

Goes to show we know squat about 'em


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PostPosted: 20 Sep 2012, 08:39 
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Red fades at depth - coral trout look green/brown/grey underwater = good camo. Isn't it accepted understanding that most/many GWS attacks occur from the GWS charging up from below. From below looking up with the bright sky in the background the target is in shadow and appears as a silhouette. A zebra stripe suit wouldn't stop this but may deter interested sharks on the surface. But from my limited experience with whalers and tigers, I've found sharks on the surface like to bump a target first to check out if it is soft, squishy and edible. Then again, tigers also have stripes and can just randomly charge from the surface - which I know first hand! Conclusion - it's not surprising (maybe even obvious) that some sharks might see in monochrome. Sharks can be dangerous and unpredictable. Keep working scientists.


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PostPosted: 20 Sep 2012, 12:28 
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A comment was put up the site that was similar and got this response:
Quote:
You are correct that the light spectrum narrows greatly with increasing depths. We are investigating the evolution of colour vision from both angles and work is currently being undertaken to determine the molecular basis for the complement of cone pigments in a myriad of ray species. Interesting, some species of fish that dwell at even greater depths possess multiple cone types, suggesting that colour vision may be an important sensory system even when there is little light. Thus, the number and type of cones may not always correlate with the local light environment. In the case of cone monochromats, such as the wobbegong sharks and many marine mammals, the unanswered question is why they have a functional 'red' cone at all and not a rod-only retina?


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PostPosted: 20 Sep 2012, 13:43 
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Yep, evolution is pretty wacky. Many deep sea creatures create their own light source so colour comes into play. It would be interesting if they did the study on GWS, Tigers, Whalers and Bull Sharks.


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