Do fish see colour?

[Phone]

Budgie, Adam,

 

You are right. I cannot recall and have no interest in looking it up, but no light penetrates water at "some(?)" depth. As a practical matter, that depth rarely occurs in fresh water carp fishing. Actually Budgie, if carp could see color at all, it would be more easily seen. In all probability the cones of the eye aren't even active - only the rods which see only in black and white. The rods and cones in the eye do not activate or operate at the same time - one or the other.

 

Equally, "visable" light, in the vicinity of 400–790nm, is for us humans. Carp (and many creatures) see FAR further into the UV light spectrum - but probably not as "color". The number of cones in the eye dictate even the remote possibility.

 

Please understand, many predatory fish do not conform to my comments - only carp.

 

The word "color (colour) is in and of itself abstract. While it is indeed complex - carp don't see color - that part is pretty easy. The idea of color requires abstract reasoning - carp don't do that either.

 

Phone

Edit: (I might add, IMO color has a huge influance on angler confidence.)

Edited August 11, 2011 by Phone

[Dick Dastardly]

Once again this is where it becomes difficult.We are trying to understand a carps "senses" by relating them to our own.It simply doesn't work.Just because a creature does not see colour in the same way as we do ie red as red blue as blue etc it doesn't mean they can not differentiate between different colours.I often use the analogy of looking at parked cars under street light at night,we don't see the colours the same as in daylight but can see that they are different even if it is just "gray scale". Pretty sure its only around 15'-18' the everything blue comes into affect so that's not so deep.

[Phone]

Budgie,

 

You would be correct if it wasn't a physical limitation. Carp don't have sufficiant cones to see color. We see "color" at night because we already know the color as a learned response. Cones and rods do not fire at the same time - it's either or - but not both.

 

When you say differentiate do you mean carp can exersize "judgment"? Carp cannot exersize judgement, reason or show emphathy either.

 

Don't know if this is the right thread but carp after being caught 3 or 4 times are usually complety blind in at least one eye. The retina is fixed and does not dilate to very sensitive optic receptors most suited to be underwater. Fortunately most anglers are right handed and exposure to direct sunlight comes from one side on the mat or in photos. It only took 12 - 15 times each side of one minute direct eye exposure to the sun to completely blind carp. There are lots of "one eyed" carp and a substantial number of blind carp in countries where repeat captures are common. It's best if they do not receive right angle exposure to bright light (the sun or a flash).

 

Overall, vision as a sense is secondary to carp survival.

 

Bare in mind, I believe they are here for our pleasure if that's what we choose and they are just fish. - It's OK.

 

Phone

Edit: OOPS not the retina that is fixed. What do you call the little hole in your eye? The retina is where the rods and cones are located in the back of the eye.)

Edit: Ha ha, I remember it is the pupil - maybe?

Edited August 11, 2011 by Phone

[Dick Dastardly]

We see "color" at night because we already know the color as a learned response. When you say differentiate do you mean carp can exersize "judgment"? Carp cannot exersize judgement, reason or show emphathy either.

 

Don't know if this is the right thread but carp after being caught 3 or 4 times are usually completely blind in at least one eye.

 

 

Your Anthropomorphising there Phone.Carp don't need a learned response to differentiate between colours.They don't have to have any understanding of the concept of colour but they can still see that objects of different colour are indeed different as can any creature which doesn't have the same colour perception as humans. Maybe its better to say they see a difference in "shade" (rather than colour) to differentiate between different objects.If they couldn't then they simply wouldn't have sight full stop!

 

I don't want to say Rubbish but its the only thing I can think of in answer to your statement re blindness mate! Ive been involved in many studies on carp over the years and never seen/heard any evidence of such.Have you got some more facts to back up why you make this claim? I ask as in all the years Ive read your thoughts Ive never known you say anything that isn't backed up by something.

[Dick Dastardly]

NOTE: What I wrote is not correct and comes across missleading its red that dissapears at around 18-20' not blue sorry! Its that Blues become the predominant colour as they "survive" down to around 110'. Like I said its confussing!

Edited August 12, 2011 by BUDGIE

[Dick Dastardly]

Please bear with me here but I also don't understand why you say the cones don't work in carp? As I understand it humans have three different kinds of cones in our eyes, called red, green and blue that make human color vision possible. Carp have not only these as well but an additional Ultra violet cone.Surely this would give them enhanced "colour" (as you rightly say the word color isn't really correct is it and causes confusion!) vision?

 

You mention the "learned response" we humans have in differentiating colour even when it doesn't exist (the car at night scenario) Its interesting that when you dive even though the red disappears quickly your brain still detects it and "compensates" I say this as you think you still see red long after it has actually gone as this is easily proved by underwater photography.

 

But once again its hard to compare our interpretation of sight,colour perception etc with a fishes. As such I think using alternative logic to prove/disprove the question of "can fish see colour" is far better.Try a search on here as there has been some great stuff wrote on it over the years from people with different back grounds such as biology,diving,fish keeping and photography.

Edited August 12, 2011 by BUDGIE

[Phone]

Budgie,

 

I have you at a disadvantage. It was only 6pm in the afternoon over here when we started the discussion. You're up late!

 

The easy part first. Remember rods and cones in the eye, both human and carp, cannot "fire" at the same time. They are hardwired together. I copied this again from my original post, "... [we humans have] 5 – 6 million cones – his quarry, carp have ONLY maybe one hundred thousand (more blue than green or red)". Carp could use color down to about 1 meter then they rely on the rods (which by the way can detect approaching danger, motion, "edge" or shape much better).

 

Below 1 meter for all practical purposes carp do not have the physical tools (number of cones) to see color - even if they could mentally discriminate - why?.

 

Beyond that you will have to re-define "color". I could never figure why anglers were so anxious about color. Light in shades of black and white have served carp for a long long time. Color would serve carp no purpose since in the horzontial column a "color" changes at the rate of infinity to zero. First red, then green, then blue dissapear. Carp live throughtout the water column but, for the purposes of "color" they don't "know" at what depth they are encountering an object. They don't need to see at ALL to survive with their superior senses associated with the lateral line.

 

In an "air" environment "color doesn't change with altitude like it does in water where inches in depth make a huge difference.

 

No question, a thousand studies have been done. No question, "anglers" want carp to see color. Unfortunately, below 1 meter carp simply can't. Not enought tools. Small brain with even a smaller part devoted to sight and far to few cones.

 

Phone

Afterthought: Budgie, I'ts hard for most anglers to accept the way to make "yellow" is to mix red and green 50/50. And, after re-reading your last couple posts "underwater photo work" is a good example of the changes that occur in water as it absorbs wavelengths of light from short to long. I'm not a photo guy but I would not have thought red could survive anywhere near 18 ft. You sure?

Edited August 12, 2011 by Phone

[Ken L]

The easy part first. Remember rods and cones in the eye, both human and carp, cannot "fire" at the same time. They are hardwired together.

 

When I go out at night, I see shades of grey but if I look at a street light, it's orange. If I look at a TV lighting up a wall through a bedroom window, I see blue. The stuff in low light remains in greyscale but I still percieve colour.

This may of course all be down to a neat bit of processing trickery by my brain with my retinas swtitching from cones to rods for the tiny area of my visual field that I know my eyes are capable of resolving in full focus at any one time but the effect is certainly one of percieving both greyscale (rods) and colour vision (cones) simultaneously.

Nontheless, it makes me very wary of assuming an either/or function within an eye - you don't afterall have an either/or function for your left and right hands.

[Dick Dastardly]

Beyond that you will have to re-define "color". Light in shades of black and white have served carp for a long long time. Color would serve carp no purpose since in the horzontial column a "color" changes at the rate of infinity to zero.

 

I'm not a photo guy but I would not have thought red could survive anywhere near 18 ft. You sure?

 

 

Yes this (I believe) is the major point here.I'm fairly certain that carp don't see colour as we do.However they can tell (by the difference in gray scale/shade) that something we see as blue is different to something we see as red (colours just for example) The fact they can see full stop proves this as without this differentiation they simply couldn't see!

 

Your point about being able to perceive colour as we do being no advantage due to the fact it changes in the column is very poignant as well. I'm sure pressure is the way they "perceive" depth as opposed to light.

 

As for the exact depth that various colours disappear.All though this obviously depends on several factors such as clarity of water,time of day (angle of light penetrating the water) etc (and so must vary accordingly) there does seem a lot of conflict on these exact depths from source to source. Especially as we've found here the depths that red first disappears. A simple search on the Internet through various pages soon shows this! Variations between 5' and 20' can be found.I think from what Ive seen after looking at various types of source of information (photography/diving/biological/optical) that this confusion comes in both due to the constraints/concerns of each of the fields.Basically in say photography the red STARTS to disappear and as such no longer looks a "true" red.However from say a divers point of view (I tend to base most of my underwater "opinions" on what I have actually witnessed during my diving days, (all though in total honesty most of my many hours were done in nigh on zero visibility!) red is still "distinguishable" up to around 18' maximum where it TOTALLY disappears.

 

As I initially said discussing this subject is very difficult as we naturally tend to anthromophisise and confusion easily creeps in due to the terminology.

 

I'm interested in hearing why you feel so many carp are blind after being caught a few times? I have caught a few fish that have been blind in one eye but by few I mean a handful at most out of literally thousands.I am of course only able to proclaim them blind if I can see obvious damage.Whilst the idea that exposure to bright light (with most fish having no eye lid) seems feasable I just havnt seen any practical bankside evidence of such or really heard/read any thing about it.

[Phone]

Budgie,

 

Nice discussion. Perhaps we agree, shades or variations of black and white dominate carp vision. The word colour is contrived for he human condition. Because of the frequency of "success" stories involving color I am also convinced that portion of the UV light used by carp is of great importance to them (although I doubt it is "colored" to them).

 

You will not be pleased with me when I tell you how I know direct sunlight blinds carp. It was the old fashioned way. We did it. In search of the "perfect" carp bait I helped spend a huge sum of money. Some of the tests were conducted included the role of light and vision and color. A lot of fish were sacrificed. One thing we learned is in the next paragraph. Another is that in my view we learned, there is no "perfect carp bait".

 

Exposure progressing up to 1 minute at "X" brightness "X" number of times. Specimen (not in size but in service) 100% of the time had SOME optic damage after 4 exposures. Only a few fish, maybe 10, received 12 one minute exposures on both left and right sides at one hour intervals. The data was extrapolated "if - then" beyond that.

It equally amazes me that anglers for some reason "don't want" blind or one eyed carp to do well and survive. They do.

 

Phone