Showing posts with label shark. Show all posts
Showing posts with label shark. Show all posts
Friday, 4 November 2011
Wednesday, 19 January 2011
Are sharks colourblind?
http://news.bbc.co.uk/earth/hi/earth_news/newsid_9365000/9365750.stm
Extract:
If sharks' retinas cannot distinguish between different colours of light, as this research suggests, they may be totally colour-blind.
Dr Hart explained that, because sharks live underwater and many are most active at dawn and dusk, they are operating in relatively dim light.
"Rods are what humans use to see at night," he said.
"But some sharks are active at all times of the day and they have more cones and fewer rods than the nocturnal or deeper diving species. Why they are apparently not interested in colour is a mystery and one we hope to find out through further research."
It seems clear from these findings that if sharks are "attracted" to an object in the water, this is probably because of its contrast against the surrounding water, rather than it's colour.
"Bright yellow is supposed to be attractive to some sharks, presumably because it appears to the sharks as a very bright target against the water," said Dr Hart.
"So perhaps it is best to avoid those fluoro-yellow shorts next time you are in the surf."
Extract:
If sharks' retinas cannot distinguish between different colours of light, as this research suggests, they may be totally colour-blind.
Dr Hart explained that, because sharks live underwater and many are most active at dawn and dusk, they are operating in relatively dim light.
"Rods are what humans use to see at night," he said.
"But some sharks are active at all times of the day and they have more cones and fewer rods than the nocturnal or deeper diving species. Why they are apparently not interested in colour is a mystery and one we hope to find out through further research."
It seems clear from these findings that if sharks are "attracted" to an object in the water, this is probably because of its contrast against the surrounding water, rather than it's colour.
"Bright yellow is supposed to be attractive to some sharks, presumably because it appears to the sharks as a very bright target against the water," said Dr Hart.
"So perhaps it is best to avoid those fluoro-yellow shorts next time you are in the surf."
Monday, 3 January 2011
New Year's Day beach walk
We found a mermaids purse (dogfish). This is only the 3rd one we have found!
The snow on the beach is gone. There were 2 more dead seal pups washed up and the seagulls and crows had been having a go at them.
The other day there were so many dead seals washed up even a big momma :(
Our puppy found a small shark that was washed up dead and dragged it about full speed up and down the beach, growling like a savage ha ha ha
This was the small shark when we found it - the birds had been having a go at it.
Saturday, 16 October 2010
Care for the Oceans
Try the different backgrounds along the top and the different sea creatures along the left side.
Thursday, 19 August 2010
A basking shark washed up on a Lewis beach
Here is the article about the basking shark that washed up on a beach in Lewis.
Its an adult shark and there is a photo.
http://www.hebrides-news.com/basking_shark_16810.html
Its an adult shark and there is a photo.
http://www.hebrides-news.com/basking_shark_16810.html
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