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Author Topic: How do fish see colours?  (Read 3343 times)

Offline alanan

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How do fish see colours?
« on: 27/01/2010 11:51:02 »
There are many brightly coloured fish in the sea, however the as  the depth increases the colours cannot be distinguished by human sight. At ten metres the red spectrum has disappeared, and a red fish appears to be black, and as you descend other shades gradually disappear. Do fish have different abilities with sight , or if not what is the purpose of there colour?


Mod edit - I've formatted your subject as a question - please do this with any future threads to help keep the forum tidy and easy to navigate.
« Last Edit: 27/01/2010 13:39:54 by BenV »


 

Offline Don_1

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Re: How do fish see colours?
« Reply #1 on: 27/01/2010 12:28:28 »
Fish have a spherical eye which allows in more light than ours, therefore, they can see in lower light levels than us. The lens moves back and forward for focusing, unlike ours, which is stretched to alter the shape.

Most fish are receptive to UV light, with some receptive to IR light and if I am not mistaken, some can use both forms. It has also been discovered that the Scabbardfish has evolved to see violet light.

The deeper you go, the larger the fish eye becomes until you reach the point at which light no longer penetrates. Many fish at these depths have either pretty useless eyes or have no eye at all.

Brightly coloured fish tend to inhabit the more shallow waters.
 

Offline alanan

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How do fish see colours?
« Reply #2 on: 28/01/2010 06:12:51 »
Thanks mate I have always been puzzled about that & I wondered why red lures were often successful.
 

Offline alanan

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How do fish see colours?
« Reply #3 on: 30/01/2010 10:09:03 »
I have been thinking about this, I am still puzzled. As I understand the  colours of the spectrum are filtered out by sea water the deeper the descent, starting with red at a depth of 10 metres, at this depth red mullet, which are a colourful fish at the surface appear black.As the colour that we see is merely a reflection of the light in the spectrum, how can it appear red to another fish
 

Offline yor_on

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How do fish see colours?
« Reply #4 on: 31/01/2010 00:00:10 »
This one might explain some of it.

ROYGBIV.

They have also a very effective silvery coating intensifying the light caught by their eyes. There is also an prehistoric fish living in Australia that seems to have the same color vision as we humans, don't remember its name, but I think it existed in some few rivers there, and was almost extinct by now.

==
Like you see it as red and knowing that this color stops at a certain depth you wonder why it is red as it goes that deep. But when you 'light it up' in ultraviolet you will see what another fish really see by that 'red color.'

==
They invented the disco light :)
« Last Edit: 31/01/2010 00:07:19 by yor_on »
 

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How do fish see colours?
« Reply #4 on: 31/01/2010 00:00:10 »

 

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