I was sidetracking PJ's celebration of painting eddie bombs for the fun of it (https://alantani.com/index.php/topic,38596.0.html (https://alantani.com/index.php/topic,38596.0.html)), so I decided to move the science-based topic to a fresh thread.
So which colors are going to make a difference to tuna according to the best available science?
Uhh, blue and...
That's it. Blue is the only color that they can see. They are colorblind. OK- one study found a minimal number of violet receptors in yellowfin eyes, but not enough to change the assertion that tuna are effectively colorblind.
On adult yellowfin tuna, the rod cells and cone cells both respond in a narrow blue range with a peak wavelength around 485 nm. That is a makerel-ish kind of blue with a tinge of green in it Other species of tuna are in the same ballpark. To get an idea -take a look at this chart:
(https://chem.libretexts.org/@api/deki/files/54205/787px-EM_spectrum.svg.png?revision=1)
Here's a quote:
Although tunas have two classes of cones (see review in Fritsches et al., 2000), electrophysiological measurements indicate only a single luminosity-type spectral sensitivity curve at photopic levels, peaking in the blue-green around 490 nm. Thus they are considered to be cone monochromats and, therefore, color blind.
Source: https://www.researchgate.net/publication/248924262_Developmental_Changes_in_the_Visual_Pigments_of_the_Yellowfin_Tuna_Thunnus_Albacares#read
Lots of other good stuff in this paper - including finding some cone cells that picked up violets (peaking around 425 nm) . These were concentrated on the top front of the eye (most important for visual feeding), so they probably serve a purpose, but are scarce enough to not change the conclusion that yellowfin are also colorblind. From the same paper:
The function of the violet cones is obscure. Nevertheless, they are associated with the major optical axis – i.e. directed toward the sea surface. The presence of a violet absorbing visual pigment does not negate the earlier suggestions that tunas are color blind, but certainly tuna should no longer be considered isochromats
Lots of other papers out there. All the same conclusion. They figure this out by examining chemicals (opsins) in the receptors (rod and cone cells) and determine which wavelengths of light cause them to generate an electrical impulse. They also do some more gruesome experiments by flashing different light wavelength on freshly extracted eyeballs and checking for electrical current coming out toward the ganglia (nerve bundles that collect signals).
Not all species of fish are colorblind. But you might be surprised how common colorblindness is among the glamour species of saltwater fishing. Especially once you get past the shallows.
This has been known for decades, and seems to be pretty settled science. But the fishing community is highly resistant.
Now here is the tricky part: Pretty much all the colors we recognize as humans are not a reflection of a single wavelength, but a combination of wavelengths. That hot pink lure that seems to be working probably has a big chunk of blue of the right frequency in it. But that same paint job would be seen more by the tuna if it had more of the blue, and less of the red that the tuna can't see.
And for some reason we are fixated on color when there is much more important (and interesting!) aspects of the visual systems of fishes. In the meantime:
stay tuned for "SCIENTISTS REVEAL HOT COLORS FOR MARLIN LURES!!!" :P
-J (AKA- Mr Buzzkill)
Any info on which color is best for albacore ? ...and is there a difference in their visual spectrum at night ?
Albacore should be the same as the rest of the tuna - and only see blue. I think that there are two color possibilities for daytime near surface: blue so that the fish can see it with the higher acuity blue cone cells, or anything but blue, so that the lure stands out from the blue water around it. There is some stuff written about how visual systems enhance edge imaging - but don't remember how they figured it out and if it applies to fish.
BTW My favorite (daytime) tuna flies have lots of black and flash on them. but I am an outlier.
Some fish species physically move the rod cells (more sensitive, less accurate) outward for the night, but in the case of tuna species, it won't matter because the both rod and cone cells peak at the same wavelegth (blue).
But mostly it is too dark at night underwater. Just some biolumincense and a tiny bit of difused light. Which meands everything is backlit and color shouldn't matter.
Back to daytime: If I was looking for something new and exciting for albacore, it might be very small black and chrome irons for those days when they are keying on small stuff but won't bite bait or the usual lures. But take this with a grain of salt -it has been decades since I have chased albacore :)
-J
I still like black or black and purple but most of my iron has a lot of blue on them.
I've always thought with both surface and yo-yo iron, it's the contrast, not the color. Scrambled egg and mint/white have a softer contrast and blue/white and black/white (good for 'cuda) have a stronger contrast. Tuna jigs at night? Color isn't important 300' down at 2am... they aren't seeing any colors! The color is to catch fishermen at the store, not fish in the ocean!
Yup.
You guys are killing me :)
Remember that black/dark is the absence of receptors firing off. So what might be a bright yellow scrambled egg jig to us humans could be the same as black to a tuna with no ability to see yellow. Same with red. No matching receptors equals the same as black.
But to pick on myself for a bit: While the blue receptors on tuna species peak at 490 nm, they get decent but weaker reception from about 460 to 510 which means mostly blues but leaking well into the greens.
Since weaker reception could either be from a less than ideal wavelength or simply less brightness (AKA amplitude- light waves have both length and height), I don't expect that tuna can tell blue from green the way we can. They would need both blue and green receptors to tell the difference. Such is the life of a monochromat...
You can play with the wave length to display color with this tool:
https://405nm.com/wavelength-to-color/ (https://405nm.com/wavelength-to-color/)
-J
I throw any surface iron as long as it is a blue and white Salas 7x, or the same color smaller iron for albacore. The iron I have had the best albacore luck with is the blue and white Salas 6x yo-yo. Completely factual, I in no way have caught enough to call it a sample that meets statistical significance, but I do appreciate that I have science in my corner. I am still convinced that disruption of background energy is as significant as anything else. It works for me for decades, don't see why it doesn't work for fish.
At the end of the day, smashed lead with a hook in the right place.
The Man
Since everything is just varying shades of blue, it seems that the pattern would be more important than color. For the pattern to get their attention it should have as much contrast as possible. That would be black and white.
I'm a believer in using flash material. It goes black-white-black-white and increases the illusion of motion.
This is an interesting topic and I'm glad it got it's own thread. Loosely related by my understanding bass see green and red only. Color-wise I have the most success with purple lures. I can't back this up empirically but I believe it's because it's a color they can sort of see. I assume it probably looks, to bass eyes, like a weird looking red. Maybe that makes it look enticing?
I also get hits on green lures but it always seems to be small bass hitting those.
Quote from: Ron Jones on June 23, 2024, 01:07:18 AMI throw any surface iron as long as it is a blue and white Salas 7x, or the same color smaller iron for albacore. The iron I have had the best albacore luck with is the blue and white Salas 6x yo-yo. Completely factual, I in no way have caught enough to call it a sample that meets statistical significance, but I do appreciate that I have science in my corner. I am still convinced that disruption of background energy is as significant as anything else. It works for me for decades, don't see why it doesn't work for fish.
At the end of the day, smashed lead with a hook in the right place.
The Man
We seemed to be hard wired to giver lure color every benefit of the doubt :)
I do agree with the comment about "disruption of background energy", which I was referring to as the halo/backlight effect. One of the benefits for writing this stuff up is double checking my own assumptions and trying to reconcile the scientific data with the observations from you folk. My theory on lure color has evolved since starting this thread.
I am warming up to the idea that blue is camouflage in a bluewater environment with no structure, and that the cone cells in tuna eye (concentrated on the front top for looking up) are used for their higher acuity (better resolution) for profile search by looking for the blue/not blue boundary between water and bait.
From an open ocean predator's view, blue is empty water, and anything that is not empty water could be food. Now the prey has evolved with reflective and blue coloration to look like open water as best as possible, and the predators have evolved to better decipher those boundaries between real and imitation empty water, which would allow them to identify a profile of an individual target that can be pursued and subjected to the taste test. An underwater evolutionary arms race of hide and seek, sort of like Ron's old line of work.
If this theory is correct, we have two lure coloration strategies. Either go for completely standing out (any color that is out of range for tuna rod and cone cells - it shouldn't matter much which one), or go for the look of a baitfish slightly failing to to camouflage, giving a the impression of a short window of opportunity that might fire off a strike reflex. Tuna brains are all about fast and efficient processing.
Your guess is a good as mine here, but I would tend toward the former in darker conditions and the latter closer to the surface in brighter daylight. But it is a just a slightly "edjumacated" guess.
This theory is consistent with us all having our favorite colors, but not the same ones, with blues and whites coming into the mix more than others for daytime.
This also partially covers Steve's comment about patterns. I'll try to respond to the rest next. I have some chores backing up that I really don't want to do :)
-J
Good info in this thread.
I have personaly been to 280' below the surface in verry clear water, not a smart thing for a sports diver but we planed the dive and had tanks staged at decompression stops. At that deeph all colors with the exception of black and grey are black and grey because the other spectrum does not penetrate. Black is always black. This is why deep water bottom fish tend to be red and orange blotched, good camouflage at depth.
On a side note large amounts of glow is not common in nature and my preferance for deep jigs is little or no glow.
Very interesting, thanks for sharing this topic.
Buzzkills are needed to eliminate misconceptions based on flawed human thinking.
Just a thought, but it seems like "something" is missing in our understanding of how fish see and react. Probably just a flawed hunch.
Maybe massive amounts of data are needed to test statistically how fish "might" see and react to it...
Quote from: oc1 on June 23, 2024, 06:21:02 AMSince everything is just varying shades of blue, it seems that the pattern would be more important than color. For the pattern to get their attention it should have as much contrast as possible. That would be black and white.
I'm a believer in using flash material. It goes black-white-black-white and increases the illusion of motion.
Well (I think) that depends...
If the predator is looking for a profile, a pattern can break up the profile. Many (but not all) bluewater species have patterns-so it must serve a purpose. Stripes on a skipjack, squiggly lines on a mackerel, and so on. These can work to break up an individual profile, or make it harder to pick out one individual from the school.
For example, single black spots are probably false eyes. Predators can use the target's eye to determine how to attack (fish don't swim backwards too well). Species that hang out in schools tend to have the spot near the head- it makes a tight pack of fish look like a wall of eyeballs. Fish that do not frequently group so tightly tend to have the spot near the tail, presumably so the predator cannot tell which end is the front.
Another example- Marlin are a major predator of dorado (mahi) and have (non) color vision capabilities very similar to tuna. Taken that green just looks like a fainter blue to this type of vision- that green with random blue dots coloration makes it easy for dorado to see each other, but harder for billfish to make out a dorado profile. It looks like a gaudy paint job to us humans but it is probably camo to a billfish.
If you just want the lure to be seen- any pattern is unlikely to be as effective as a solid color- any color that the rods/cones won't respond to for fish that are looking up or against something like a shallow sand bottom, and something white for fish looking down. Going between displaying light and dark as the lure wiggles might match the pattern of a disoriented baitfish that is not keeping right side up very well. I think this might be what you are getting at wwith the "illusion of motion" concept?
In regards to flash: A highly reflective surface is used by fish as camouflage as well. Each row of scales are at a different angle, reflecting light in different directions(difusion), and also reflecting the colors and shades that are around it, making it harder for a predator to make out a profile. Bonefish are the masters of this camouflage.
I am sure that you have seen this one: a bonefish cruising in the grass right in front of you with each scale reflecting seperate bits of sand bottom, coral, seaweed or whatever is around it. The fish is almost invisible. All you can see is the eye and/or the shadow underneath it. but if it rolls a bit, the change in angle makes a humongous flash that you can see easily at 50 yards, No doubt that predators key on this as well. A fish that is rolling is vulnerable and easy to find.
Don't know why, but this attraction to flash seems to be species or maybe situation specific. A 5 lb skipjack will be all over a gigantic chrome crocodile, but you can scare off a 50 lb roosterfish in the shallows if you have more than a strand or two of flash in your 4 inch fly. Sometimes a big flash is better, sometimes no flash, sometimes something in between. Flash is useful in almost all situations for catching fishermen's money in tackle shops. Right up there with with those "realistic" photo style finishes.
BTW: the vision data is from the scientific literature, but the conclusions and conjecture are mine. While I am doing my best to be logic-based here, other folk may come to different conclusions. Not trying to convince anyone- just sharing what I have learned and am learning more myself in the process.
It's all good.
-J
Quote from: JasonGotaProblem on June 23, 2024, 02:25:49 PMThis is an interesting topic and I'm glad it got it's own thread. Loosely related by my understanding bass see green and red only. Color-wise I have the most success with purple lures. I can't back this up empirically but I believe it's because it's a color they can sort of see. I assume it probably looks, to bass eyes, like a weird looking red. Maybe that makes it look enticing?
I also get hits on green lures but it always seems to be small bass hitting those.
I seem to remember reading that largemouth bass have red and green receptors, but not blue- so anything from green through yellow to red should probably register. Makes sense. Lots of the blue light is going to be absorbed by algae in their environment. Not too many crystal clear weedless bass lakes.
A pure violet color is not going to be visible if the above is accurate. Violet is too far from green in wavelength to be likely to get picked up. But what we see as purple is usually going to be some combo of red and blue waves. The red wave component will still register.
Blue was a hot soft plastic color for the bass crowd for awhile, and blue is just going to be black to a bass. So even if your purple turns out mostly blackish to a bass, it doesn't mean that it won't work.
-J
Quote from: Keta on June 23, 2024, 06:38:34 PMGood info in this thread.
I have personaly been to 280' below the surface in verry clear water, not a smart thing for a sports diver but we planed the dive and had tanks staged at decompression stops. At that deeph all colors with the exception of black and grey are black and grey because the other spectrum does not penetrate. Black is always black. This is why deep water bottom fish tend to be red and orange blotched, good camouflage at depth.
On a side note large amounts of glow is not common in nature and my preferance for deep jigs is little or no glow.
Exactly.
I haven't gone past 120ft or so, but I think this is all much more obvious to us folk who have been underwater. Colors go away quickly, it is hard to see far or clearly even the best conditions and it gets real dark down there at night. However there are differences. A pure bright red or yellow will still be black to a tuna right at the surface.
The glow popularity is kind of weird to me too. Folks don't expect a flashlight with hook on it to be a good idea for a lure, but are OK with a full glow paint job. I have taken just a strip or two of glow off a vinyl skirt to mix in with the regular stuff on my octopus jigs, but I can't get enthused about the full glow approach. But at least it is something the fish can see and could make a difference- positive or negative difference is the question.
I have some thoughts on using glow more strategically, but will save for another day.
-J
Keep it up.
Quote from: jurelometer on June 23, 2024, 11:14:14 PMQuote from: Keta on June 23, 2024, 06:38:34 PMGood info in this thread.
I have personaly been to 280' below the surface in verry clear water, not a smart thing for a sports diver but we planed the dive and had tanks staged at decompression stops. At that deeph all colors with the exception of black and grey are black and grey because the other spectrum does not penetrate. Black is always black. This is why deep water bottom fish tend to be red and orange blotched, good camouflage at depth.
On a side note large amounts of glow is not common in nature and my preferance for deep jigs is little or no glow.
Exactly.
I haven't gone past 120ft or so, but I think this is all much more obvious to us folk who have been underwater. Colors go away quickly, it is hard to see far or clearly even the best conditions and it gets real dark down there at night. However there are differences. A pure bright red or yellow will still be black to a tuna right at the surface.
The glow popularity is kind of weird to me too. Folks don't expect a flashlight with hook on it to be a good idea for a lure, but are OK with a full glow paint job. I have taken just a strip or two of glow off a vinyl skirt to mix in with the regular stuff on my octopus jigs, but I can't get enthused about the full glow approach. But at least it is something the fish can see and could make a difference- positive or negative difference is the question.
I have some thoughts on using glow more strategically, but will save for another day.
-J
Quote from: jurelometer on June 23, 2024, 11:14:14 PMQuote from: Keta on June 23, 2024, 06:38:34 PMGood info in this thread.
I have personaly been to 280' below the surface in verry clear water, not a smart thing for a sports diver but we planed the dive and had tanks staged at decompression stops. At that deeph all colors with the exception of black and grey are black and grey because the other spectrum does not penetrate. Black is always black. This is why deep water bottom fish tend to be red and orange blotched, good camouflage at depth.
On a side note large amounts of glow is not common in nature and my preferance for deep jigs is little or no glow.
Exactly.
I haven't gone past 120ft or so, but I think this is all much more obvious to us folk who have been underwater. Colors go away quickly, it is hard to see far or clearly even the best conditions and it gets real dark down there at night. However there are differences. A pure bright red or yellow will still be black to a tuna right at the surface.
The glow popularity is kind of weird to me too. Folks don't expect a flashlight with hook on it to be a good idea for a lure, but are OK with a full glow paint job. I have taken just a strip or two of glow off a vinyl skirt to mix in with the regular stuff on my octopus jigs, but I can't get enthused about the full glow approach. But at least it is something the fish can see and could make a difference- positive or negative difference is the question.
I have some thoughts on using glow more strategically, but will save for another day.
-J
The red rip rollers with the lumo dots were real popular a couple of years ago! I still see guys using black light flashlights on their glow jigs. I just smile and drop my non glow jig.
Quote from: Gfish on June 23, 2024, 06:50:06 PMBuzzkills are needed to eliminate misconceptions based on flawed human thinking.
Just a thought, but it seems like "something" is missing in our understanding of how fish see and react. Probably just a flawed hunch.
Maybe massive amounts of data are needed to test statistically how fish "might" see and react to it...
Not a flawed hunch. Jason was getting at this too. I think it works something like this:
Enough photons from a single light wave of the right wavelength hit a single rod cell to cause it to fire off an electrical impulse. this impulse gets sorted and processed a bit with all the other light signals by a ganglia and then passed on to the brain that has non-specific layer upon layer of neurons (more variable electrical sensors) that are constantly self wiring and unwiring to to other neurons. A larger brain with lots of neuron activity networking through lots of layers allows for advanced imaging processing, even including stuff like past experience (us humans), but be prepared to consume a lot of electricity (calories), and take a long time to get through all the layers for processing. The other choice to to get by with less. Fish have much smaller, less complex brains- they have chosen the less-is-more strategy.
An example: A species of tetra will go into mating mode when it encounters the right shade of red. Same with mantis shrimp. Not much processing going on here. the source doesn't have to be the right species, or even a species at all. It can be a paint chip. Sometimes simpler is better, or at least good enough. It is definitely more efficient and faster, and is the evolutionary path taken by fish. My guess is that if we think more in terms of fewer simple mostly short term memories, and rest being input triggers to hardwired action, we probably will get closer to how a fish perceives and reacts to its surroundings. This does not mean that fish can't do some pretty impressive stuff. A salmon can cross the ocean and find the same chunk of freshwater it was hatched in, even if it is a a couple hundred miles upstream. There are lots of humans that couldn't find a liquor store without google maps guiding them in.
Can't go any deeper than this anyways. Fish are pretty tight lipped when you ask them anything about anything. Not too interested in the philosophy end of it myself.
But those switches! Watching how fast a tuna or dorado will react to a live bait hitting the water compared to any lure or fly makes me think that there is something useful and learnable out there.
-J
Full glow is my go too for halibut at depths of 300 feet plus. I know Ted does not agree for his area. Sorry for the short post. >:D
Todd
The neuron explanation is spot on, and explains why energy identified via the "lateral line" (it isn't actually a line) have priority over vision. Predator fish especially behave similar to a VLF(P) system. Quiet spots in a loud background stand out. I don't think anyone knows if this is to identify immobilized prey, or just prey in general due to their size. Bait fish are quieter than tuna, and everything is quieter than shrimp or clams. A rapidly moving quiet spot is very distinct against a high background noise environment.
Quote from: Ron Jones on June 24, 2024, 03:00:19 AMPredator fish especially behave similar to a VLF(P) system. Quiet spots in a loud background stand out. I don't think anyone knows if this is to identify immobilized prey, or just prey in general due to their size. Bait fish are quieter than tuna, and everything is quieter than shrimp or clams. A rapidly moving quiet spot is very distinct against a high background noise environment.
Interesting... Are you talking about the lateral line here?
Quote from: Hardy Boy on June 24, 2024, 12:40:31 AMFull glow is my go too for halibut at depths of 300 feet plus. I know Ted does not agree for his area. Sorry for the short post. >:D
Todd
250 characters or less is always more enlightening /s Going past my limit, but I would say do some testing with just a bit of glow on the lure...
-J
Many (most?) fish are pretty stupid and reactive feeders. Especially real deepwater specimens - notice how they all have enormous mouths compared to the overall size of the fish? Down there if it seems edible you eat it and ask questions later. In this circumstance, I think glow (and clip-on disco lights) are useful just to get a fish to come and investigate what is going on, perhaps from a distance beyond that at which they would otherwise normally detect your line. However, I have anecdotal "evidence" (well, actually data but from a sample size that makes it interesting but not quite scientific) that excess glow is actually a deterrent to some deepwater species.
I do a lot of jig fishing in 200-250ft and for a long time my go-to was a black jig with black skirts and not a hint of anything else. The latest season, it was a yellow/orange jig that consistently performed the best. Who knows. I think what is more important to a fish when it comes to color is that it resembles something they might eat normally.
Right on Dave, in my experience fishing cedar plugs for tuna, the blue painted ones get hit the most. Rooster fish will hit school bus type plugs. Caught 2 last week. Dominick
Quote from: Hardy Boy on June 24, 2024, 12:40:31 AMFull glow is my go too for halibut at depths of 300 feet plus. I know Ted does not agree for his area. Sorry for the short post. >:D
Todd
Halibut are not afraid of much and are agressive feeders. I use 12"-18" shell squid over my baits, usualy blue and white or black and purple. Both have 2 lines or several dots of glow.
Gary the butt man uses lights over his bait and out fishes everyone in Glacier Bay. Dominick
This thread keeps straining to go into "my favorite color" territory. But the point of the thread is that tuna don't see in color. Most of the species mentioned are also monochromats, although as we get to inshore or waters away from the equator the single color becomes green instead of blue. Halibut ar green monocramats, if I remember correctly.
Don't know about color vision in roosterfish, but I would guess at green monochromatic, something in low 500 nm peak, and favoring rod cells density over cones as roosterfish feeding activity is heavily tilted toward dawn and dusk- got that from a study on roosterfish tagging.
I am not one of those roosterfish junkies, but have gotten enough time in to convince myself that size, volume and speed of fly presentation is the key to getting bites. But put 12 saltwater fly fishermen in a room to talk about roosterfish flies and 13 of them will want to talk about nothing but color :).
I'll do a quick search on the roosters.
-J
Lots to cover on feeding triggers, both visual and non-visual. Color is a tiny part of the equation in the underwater environment where access to most wavelengths is so restricted. And there are some really interesting studies on fish vision out there.
I have been tempted to start a separate thread on what I think are the more important aspects of fish visual behavior, but it is a lot of work since my "research" is pretty scattergun with plenty of holes to fill in. Plus many folk won't read anything but a short post, and the conversation is going to keep sliding toward off-topic favorite lure stuff, where folk get more enthusiastic and have more to contribute. You guys get to talk about whatever you want, but for me: Meh...
-J
Quote from: jurelometer on June 24, 2024, 12:15:55 AMEnough photons from a single light wave of the right wavelength hit a single rod cell to cause it to fire off an electrical impulse. this impulse gets sorted and processed a bit with all the other light signals by a ganglia and then passed on to the brain that has non-specific layer upon layer of neurons (more variable electrical sensors) that are constantly self wiring and unwiring to to other neurons. A larger brain with lots of neuron activity networking through lots of layers allows for advanced imaging processing, even including stuff like past experience (us humans), but be prepared to consume a lot of electricity (calories), and take a long time to get through all the layers for processing. The other choice to to get by with less. Fish have much smaller, less complex brains- they have chosen the less-is-more strategy.
I should also point out that mammals have a visual cortex- the "graphics processor" part of the brain which does not exist in other animals including fish. But it turns out that fish are actually able to pull off some of the same visual functions without the big fancy brain parts that scientists originally thought were necessary.
I mentioned edge image enhancement earlier. The idea here is filling in the gaps in a somewhat reliable fashion when the receptor cells do not pick up a full image. We know that humans do this by showing them optical illusions and asking them what they see. Turns out that is is sort of a way to ask fish what they see by training then with food or other incentives. Yep. Fish species (to varying degrees) "see" optical illusions, which means that their visual system is adapting the input to make it more useful.
Another paper claims that fish species that can see in color still favor shading and shapes over color for pattern recognition, which is opposite of us humans- probably because the availability of color underwater is much less reliable. This gets back to Steve's question about patterns. So yes, some species are pretty good about seeing patterns.
I'll try and find the papers again and paste in the links and some examples.
-J
Quote from: boon on June 24, 2024, 04:39:00 AMI do a lot of jig fishing in 200-250ft and for a long time my go-to was a black jig with black skirts and not a hint of anything else. The latest season, it was a yellow/orange jig that consistently performed the best. Who knows. I think what is more important to a fish when it comes to color is that it resembles something they might eat normally.
That first assumes that they can see the color. At 200 feet there is absolutely zero yellow and red light available. And the target species will have zero ability to see those colors. So there is either something different with the two jigs, or the catch numbers are not a clean sample set- you would have to be switching back and forth between paint jobs on every drop or two to get reasonably accurate samples- and somebody has to start the drop for you, so you don't know which color you are fishing :)
But if your goal is to catch fish, who am I to argue with simply continuing to do what works.
-J
Quote from: jurelometer on June 25, 2024, 02:01:41 AMThat first assumes that they can see the color. At 200 feet there is absolutely zero yellow and red light available. And the target species will have zero ability to see those colors. So there is either something different with the two jigs, or the catch numbers are not a clean sample set- you would have to be switching back and forth between paint jobs on every drop or two to get reasonably accurate samples- and somebody has to start the drop for you, so you don't know which color you are fishing :)
But if your goal is to catch fish, who am I to argue with simply continuing to do what works.
-J
The science behind it all makes sense. The part I guess we don't know, and therefore we just have to speculate about, is how does it look to a fish - does a yellow jig at 300ft look exactly the same as a pink one, or a black one? If the target species primary prey is bright yellow (at the surface), at 300ft would it look exactly the same if it was bright green? If we're hoping that the color triggers some level of recognition of the lure as prey, and therefore an attempt to eat it.
I'm inclined to believe that action (both inherent and imparted by the angler) of a lure is more important for getting a bite than any particular aesthetic aspect.
From my limited use of eddy bombs a mid speed retrieve with no imparted "action" was what worked for most fish.
Quote from: Keta on June 25, 2024, 09:40:35 PMFrom my limited use of eddy bombs a mid speed retrieve with no imparted "action" was what worked for most fish.
That is, in itself, an "action" of sorts.
I do a lot of Kabura fishing. A slow wind with no rod movement at all is often what gets the bite.
True
Quote from: boon on June 25, 2024, 09:30:23 PMThe science behind it all makes sense. The part I guess we don't know, and therefore we just have to speculate about, is how does it look to a fish - does a yellow jig at 300ft look exactly the same as a pink one, or a black one? If the target species primary prey is bright yellow (at the surface), at 300ft would it look exactly the same if it was bright green? If we're hoping that the color triggers some level of recognition of the lure as prey, and therefore an attempt to eat it.
We do not have to speculate! We do know how these colors looks to a fish at 300 ft! There is nothing to see. If there are no light waves available in the frequency for that color, then there is nothing to to bounce off of objects that can reflect that frequency/color.
At 300 feet a yellow paintjob is the same as bright green. Or red, or whatever. They are all just black. Those low frequency/high wavelength light waves are long gone. They have all been absorbed and converted to heat by the water. That is why us humans with our trichromatic vision can't see any reds, yellows or greens either when scuba diving past 30 feet or so (often less).
Plus deepwater species won't have receptors for colors that don't reach them.
I respect that this is kind of non-intuitive to us humans who see color as an inherent property of an object. But color is actually just a perception. And this perception requires more than a surface coated with a specific material. It requires light waves of certain frequencies as well. Your yellow jig ain't really yellow until a yellow light wave bounces off of it and gets picked up by the red and green cone cells in your eye. Otherwise it is just black (no signal).
Maybe more on this later, but I am losing steam :)
QuoteI'm inclined to believe that action (both inherent and imparted by the angler) of a lure is more important for getting a bite than any particular aesthetic aspect.
No argument there.
-J
Not sure how deep this guy was trolling but the salmon definite saw the spoon
https://youtu.be/Fm9fdCw9K88
Quote from: jurelometer on June 26, 2024, 12:07:00 AMQuote from: boon on June 25, 2024, 09:30:23 PMThe science behind it all makes sense. The part I guess we don't know, and therefore we just have to speculate about, is how does it look to a fish - does a yellow jig at 300ft look exactly the same as a pink one, or a black one? If the target species primary prey is bright yellow (at the surface), at 300ft would it look exactly the same if it was bright green? If we're hoping that the color triggers some level of recognition of the lure as prey, and therefore an attempt to eat it.
We do not have to speculate! We do know how these colors looks to a fish at 300 ft! There is nothing to see. If there are no light waves available in the frequency for that color, then there is nothing to to bounce off of objects that can reflect that frequency/color.
At 300 feet a yellow paintjob is the same as bright green. Or red, or whatever. They are all just black. Those low frequency/high wavelength light waves are long gone. They have all been absorbed and converted to heat by the water. That is why us humans with our trichromatic vision can't see any reds, yellows or greens either when scuba diving past 30 feet or so (often less).
Plus deepwater species won't have receptors for colors that don't reach them.
This all makes good sense to me. If there's no light of wavelength x at that depth then it's functionally black, right - black being the absence of any other reflected wavelength. Likewise for what is perceived by the brain on the basis of signals sent from the eyeball.
Someone said it before in this thread, but I guess all those pretty paintjobs really are mostly for the angler's benefit, not the fishes :d
Black and grey.
https://youtu.be/bGOx0az3hUE
At 100ft
Interesting videos Shibs, but I wouldn't take too much from being a human looking at a GoPro shot with all kinds of image enhancements. The salmon do their own enhancements for their own purposes. And downrigger guys are notorious for getting depth wrong. They are usually just telling you how much line they have out on the downrigger. The smarter ones will at least tell you that depth is "on the wire" But, yes, salmon are highly visual feeders.
On the salmon videos, you can see many sideways turns when the salmon are in close checking out the lure. I wouldn't be surprised if that was using the lateral line and getting confused as to why the pressure wave was so odd compared to what they are used to chasing. When jigging for fired up groupers in shallow water, I have seen them go nuts twisting around trying to lock in with their lateral lines to get a shot at a bouncing jig that is not running away.
On salmon and color vision:
When pacific salmon species (and rainbow trout) first hatch, they have UV light receptors, but these get turned into to blue receptors (around 430 nm) as they grow up and switch from feeding primarily on plankton to larger prey. Pacific salmon do have color vision with three types of cone cells from blue to the low end of the reds. So good news for all the salmon trolling crazies out there that are big on swapping around color schemes. At least the salmon can see those colors if you are fishing shallow enough.
True UV "colors" ain't going to you no good. Adult salmon won't see them. But that is OK, because us humans can't see UV either. When we go to the tackle shop and pick out those "UV" colors that salmon fishermen like so much like purple haze, we are seeing non UV colors anyways. We wouldn't be able to pick out a highly UV reflective lure if we were staring right at it ::)
UV light is right at the borderline of the range of wavelengths that can pass through water, so it diffuses quickly and doesn't travel far, so just a near surface thing. Plus UV light damages cells. So don't plan on a long life with good acuity if you have UV receptors instead of UV filtering in your eyes. UV vision is more common on land based species and some shallower water marine life. There is such a thing as UV reactive colors (fluorescent), but we can save that for later.
One thing that we haven't covered much is the density and distribution of the various types of receptors. In addition to wavelength overlap, salmon eye cone cells are layed out to favor better reception of greens. Makes sense. They live and feed more in green water. But salmon can also be found feeding in deep water and up top in those brownish krill filled water, so it also makes sense that they have a broader range of color vision. So expect that they can see violet through blue, green, yellow, and into the reds, but best a green.
Salmon vision is pretty well studied, but I am having trouble getting past the paywalls to get the details from the scientific papers. Usually I can sleuth out a public domain copy, but little joy so far.
BTW- Absolutely nothing on roosterfish vision. There are hardly any studies of any kind on roosterfish. They are a commercially unimportant species, and not easy to study. There was one tagging study that found that roosters spend dusk to dawn in very shallow water, and move into deeper water (lie 30 to 70 feet) during daylight hours. We should expect their vision to be optimized for that lifestyle. But I have seen lots of roosters midday in the shallows, especially smaller ones. So...
-J
Quote from: jurelometer on June 26, 2024, 05:55:13 PMBTW- Absolutely nothing on roosterfish vision. There are hardly any studies of any kind on roosterfish. They are a commercially unimportant species, and not easy to study. There was one tagging study that found that roosters spend dusk to dawn if very shallower after, and move into deeper water (lie 30 to 70 feet) during daylight hours. We should expect their vision to be optimized for that lifestyle. But I have seen lots of roosters midday in the shallows, especially smaller ones. So...
-J
They are fun to fish and sure are pretty. When people ask me what they taste like, I tell them that we let them go because they are too pretty to eat. I had the most success with rooster fish trolling with live caballito in the morning. The caballito drops about 6 to 12 inches below the surface and when it is taken by a rooster it results in a wild splash at the surface. We have used yellow Bombers in the afternoon because the lure dives (I'm not sure how deep). School Buses work popping on the surface. The hard part about rooster fishing is when to set the hook. Dominick
Katie Perry is the only answer :D Related to this, in one of my previous lives in High quality commercial printing, the things that we could do with ink on paper, at best, only covered 40% of the actual visual spectrum. You look at a printed picture of a field of flowers or a supermodel, you would think it looks great. Hold the photo up next to the real thing - suddenly it looks shabby. The missing element that we dealt with in the print shop was "saturation", - john
Quote from: Maxed Out on June 26, 2024, 09:16:49 PM....A very common saying is used in the Pacific Northwest. "Use any color lure for salmon, as long as it's green". I've personally caught lots of salmon on many different colors, from 30'on down to 450', and plenty on glow lures, but doubtful the glow had anything to do with attracting them, because a glowing lure usually stops glowing after a few minutes
Strontium Aluminate (https://en.wikipedia.org/wiki/Strontium_aluminate) glows for hours & hours and has helped my immeasurably-I use beads, tape, powder you name it.
Flashers covered in UV tape are also Very Attractive to Salmon.
I tried posting here about electrical charges affecting the Salmon bite but no one was interested.
Black boxes work.
Quote from: whalebreath on June 28, 2024, 02:14:57 AMFlashers covered in UV tape are also Very Attractive to Salmon.
I tried posting here about electrical charges affecting the Salmon bite but no one was interested.
Maybe start a separate thread on black boxes. I'll even pitch in a link to the study. I have a couple questions too.
Regarding "UV" tape: what is your definition of "UV"? Note what I mentioned earlier about UV light and UV reflectivity.
I have a little bit more to add still on fish and color vision.
-J
Quote from: jurelometer on June 28, 2024, 05:44:08 AMRegarding "UV" tape: what is your definition of "UV"?
A sick looking flash that I can actually see as long as it's not bright sunlight-if it is bright conditions I don't bother.
Quote from: whalebreath on June 28, 2024, 02:14:57 AMI tried posting here about electrical charges affecting the Salmon bite but no one was interested.
We are interested. I tried to search for your mention of electrical charge but could not find anything. Please post in a new posting your information on electrical charge attracting fish. Dominick
I use a uv spray. Reflect the light make them bite !! That's what the can says. :d
Todd
Quote from: Dominick on June 29, 2024, 04:03:10 PMQuote from: whalebreath on June 28, 2024, 02:14:57 AMI tried posting here about electrical charges affecting the Salmon bite but no one was interested.
We are interested. I tried to search for your mention of electrical charge but could not find anything. Please post in a new posting your information on electrical charge attracting fish. Dominick
Look up "Black Box".
A friend of mine in Alaska got a grant from the University of Alaska to research electric fields effect on salmon for commercial trolling. The results were that controlling the elctric fields worked for the study. I do not know if there was any follow up research.
Quote from: Keta on June 30, 2024, 02:01:07 AMQuote from: Dominick on June 29, 2024, 04:03:10 PMQuote from: whalebreath on June 28, 2024, 02:14:57 AMI tried posting here about electrical charges affecting the Salmon bite but no one was interested.
We are interested. I tried to search for your mention of electrical charge but could not find anything. Please post in a new posting your information on electrical charge attracting fish. Dominick
Look up "Black Box".
A friend of mine in Alaska got a grant from the University of Alaska to research electric fields effect on salmon for commercial trolling. The results were that controlling the elctric fields worked for the study. I do not know if there was any follow up research.
shocking! 8)
Quote from: whalebreath on June 03, 2022, 05:29:34 AMQuote from: Benni3 on May 30, 2022, 04:24:39 AMGreat video...I think you need some dr juice scent to kick the flavor or maybe some bacon fat on the end of the hook to get them to bite
Scent is only marginally effective on trolled Salmon baits commercial fishermen in British Columbia use it very little if at all.
Quote from: Dominick on May 31, 2022, 01:21:08 AMIt seems to me that your lure is flipping around too much. We use.....
That's wrong-any bait a Salmon can swim up to it can and will catch & kill; what you're seeing is Salmon rejecting the lure because it's getting a small electrical shock when it tries to bite it-that's why they're all turning away like that it's right there in front of you just look at what happens with a 'hot boat'.
This is an old old subject here in BC all the commercial boats run 'black boxes' that regulate the production of electric current by the passage of the downrigger wire through the electrolyte-which of course is saltwater.
Sport black boxes are available on the market or you can perform due diligence and carefully go over every source of electrical current on your boat to make it's not 'running hot' or producing too much current causing exactly what we see in that video.
This website by an ex-commercial fisherman has some info I use his gear and swear by it
https://lurecharge.ca/
Yup. Every hull has a unique electrical charge due to dissimilar metals and the electrolyte, salt water. Aluminum hulls are higher current , a porly wired boat, usualy grounding, makes a "hot" boat and they fish porly. Stainless cable carries the current down to the fish.
I use 300# Spectra downrigger cable and no black box and I think it helps.
I would strongly encourage a separate thread for black boxes and electric current. This thread is about color vision in fish. It doesn't help folk who might come by to read one topic to have to wade through another.
Thanks!
-J
Quote from: Hardy Boy on June 30, 2024, 01:17:05 AMI use a uv spray. Reflect the light make them bite !! That's what the can says. :d
Todd
I hope Todd can get a refund on that UV spray. :P
In order for a UV reflective coating to make a lure more visible to a fish that you are trying to catch, the following has to be true:
1. The target species has eyes with receptors sensitive to the UV wave length of the product.
2. There has to be enough UV light energy reaching the surface of the water from the sun.
3. The UV light wavelength must penetrate to the depths that you are fishing in sufficient quantity.
——-
Unfortunately in the vast majority of cases, we have a 0-3 score.
——-
1. Nope: Most marine species that we target do not have UV sensitive receptors, and in fact, some have chemicals in the eye to filter out UV light, as UV light is destructive to cells. Note the paper referenced earlier on Pacific salmon vision.
2. Not much. Although UV waves are powerful, UV light makes up a small percentage of the total light energy from the sun that reaches sea level. The sections in red in the chart below show the total energy by surface area by wavelength: very little available energy from the 360- 400 nm range that makes up UVA light.
(https://alantani.com/gallery/38/11927-300624042044.png)
3. Not where we do most of our fishing. UV light can penetrate to reasonable depths in extremely clear water. But it does not penetrate well in water that has stuff in it. Especially organic stuff. Like algae. This water has to be relatively devoid of life, and not turbid, Which means it has to be out in the middle of nowhere, toward the equator, and devoid of life. Not a spot where most of us fish. The following chart shows the depth where 10% of the surface UVA light remains, at midday sun. Note that most of the waters that we fish are masked out (white) due to some issues with the formula, but we can still see the penetration depth tapering off rapidly as we move away from the equator and/or into waters with more suspended organic matter.
(https://alantani.com/gallery/38/11927-300624042223.jpeg)
Source: https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1002/jgrc.20308 (https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1002/jgrc.20308)
[Note: I couldn't get past the paywalls to find better data for nearshore/inshore UV light penetration. I would be grateful if anyone that finds something better would post it]
Conclusion: For most of us saltwater fishers, UV reflective coatings are unlikely to provide a benefit. UV reactive colors (i.e., fluorescent) have a chance of providing a benefit at shallower depths, the shallower the better. It looks to me like most of the "UV" colors that we see on lures are actually UV reactive.
-J
A bit more on UV reactive, AKA fluorescent colors.
When a light wave comes in contact with an atom, the photons in the light wave interact with the electron clouds in the atom. The reaction depends on the compatibility of the two frequencies. The photon energy can be absorbed - that is why dark colored objects(less reflected light) get warmer in the sun than light colored objects. Or the photon can get kicked back out on the same frequency that in came in on, producing a light wave of the original wavelength. This is what causes most of the colors that we see.
And then there is fluorescence. The photon gets kicked back out, but this time on a lower frequency. Chartreuse is a popular fluorescent color for fishermen. That glowing chartreuse is a result of UVA through violet into blue waves on the way in, but green waves on the way out.
I don't know what causes fluorescent colors to be more vivid. I suspect that it is the extra energy from the UV waves that were not visible to humans, but now contributes to visible light after the wavelength change to green.
Another potential benefit to this shift is producing more vivid large wavelength colors at depth. For example, there is a saying among striped bass fishermen that "if it ain't chartreuse, it ain't got no use". No coincidence that color perception for striped bass peaks on the yellowish side of green. A fluorescent chartreuse lure will convert some blue light waves into a green that is more visible to the higher acuity rod cells in the striper's eye.
Same probably goes for other fluorescent colors, but they should map into the specific color sensitivity of the target species. There is the possibility of fluorescing our way into less visibility with the wrong color choice.
The more UV light available, the more that these colors should pop.
-J
We DO need a seperate thread on "black boxes" since that is something I am not familiar with. And would now be a good time to mention we start a "scent" thread as well? (Curse me all now!). Scent is major voodoo for lobster fishing.... -john
Agreed. Scent, motion and overall size are the important things. Everything else is fluff.
The topic here is lure color and its relation to vision in fish. There is a button at the top of every sub-forum for starting a new thread. I suggest giving that a try for other topics.
It is to unwieldy to have a single thread on all aspects of fish behavior that relate to catching fish.
Thanks,
-J
Totally agree
Quote from: whalebreath on June 29, 2024, 03:04:09 AMQuote from: jurelometer on June 28, 2024, 05:44:08 AMRegarding "UV" tape: what is your definition of "UV"?
A sick looking flash that I can actually see as long as it's not bright sunlight-if it is bright conditions I don't bother.
Yep,
Tackle is designed to catch fishermen, not fish! :d
Quote from: jurelometer on July 01, 2024, 07:19:16 AMThe topic here is lure color and its relation to vision in fish. There is a button at the top of every sub-forum for starting a new thread. I suggest giving that a try for other topics.
It is to unwieldy to have a single thread on all aspects of fish behavior that relate to catching fish.
Thanks,
-J
soup nazi
And to think I was getting to branch off (within this thread) to discussing how these lures make fish feel, on the inside.
Quote from: oc1 on July 01, 2024, 06:55:47 PMQuote from: jurelometer on July 01, 2024, 07:19:16 AMThe topic here is lure color and its relation to vision in fish. There is a button at the top of every sub-forum for starting a new thread. I suggest giving that a try for other topics.
It is to unwieldy to have a single thread on all aspects of fish behavior that relate to catching fish.
Thanks,
-J
thread nazi
Play nice.
I started a new thread for the folk interested on the do's and don'ts of topic veers:
What is our resposibility for staying on topic in a thread? (https://alantani.com/index.php/topic,38673)
Please place any comments there
See, that wasn't hard :)
-J
Dave started the thread, so...
Great reading so-far. Thanks to Jurelometer(what does that noun mean?)and others for the research and contributions.
Godda find-out about electricity and fish evasion and(or) attraction. Just on my yak there's the fish finder and then there's a 29V, up to 430watt motor used when I troll or move. Can see a disturbance reflected on the finder screen that goes all the way to the bottom when I start the motor after a stop...
Another thread on this would be a good idea.
OK, back to business.
On popper colors that someone mentioned earlier:
Here is the funny thing about poppers.
Since poppers float on the surface, the fish can't see the paint job above the waterline. Below the waterline, the fish is looking up into the sun through the Snell's window, which means all they are seeing is a sillouette sourrounded by bright light.
Plus nearly every commerically made popper is white below the waterline anyways.
Now add in the turbulence from the popper action.
Now add in that tuna are effectively colorblind...
But that hasn't stopped Saltwater Sportsman from doing several aritcles on tuna poppers that feature color schemes- "Top Captains favorite tuna poppers" blah, blah, blah. Well they do have to appeal to advertisers that sell lures.
Using a highly visible color can be useful if you are casting far or if you break off the popper and want to go looking for it. Maybe going for all black, or at least below the waterline would keep the lure more visible at stops between pops, but I am reaching here. Plus a black popper is going to be a hard sell. Who wants plain black when you can get Frostbite Cherry (sadly, that is a real color scheme)?
I can't think of a lure style where the paint job could be more irrelevant. I have been working on a new type of saltwater popper, and I don't bother painting the prototypes at all. Well, I did paint one Katy Perry colors to get a laugh from the Zoom group, who promptly also requested a Mr Hanky color theme (thanks John...)
-J
How about clear poppers?
You never know for 100% certain if the bites occur at rest, but otherwise I would bet that "clear" poppers should look about the same. It is not like they are invisible. And then there is the seam, belly weight, wire, hooks. All visible at rest...
Not to mention that the point of working a popper is to be extremely conspicuous.
I have noticed that when tuna are on the krill or microbait, it can take a lot of casts to get a popper bite. And sometimes they will turn on to bigger lures for awhile and then back to ignoring them. This makes it easy to fool yourself into thinking that a lure change was the reason that you got bit. You have to exercise discipline and rotate out the lures at very short measured intervals, and do it enough times. I rarely am willing to put this much time and effort in. But if you are getting bit on every cast, it can be instructive to try to find lures that won't get bit and then switch back. Not proof, but at least some useful data.
Come to think of it, a chrome popper might flash a bit if it rolls, but most poppers are designed not to roll so that they don't spin when you pull them fast.
-J
In my opinion color is far less a factor as I can action and sound, especially at depth.
If 50% plus of the fisherman are using a xx colored xxx lure and 50% plus of the fish are caught on them only proves the math.
I am the guilty party for hijacking your thread when I changed the subject and asked which colors salmon see. The title is about tuna, not salmon, so I removed my posts and hope you accept my sincere apologies. I know zilch about tuna, and will refrain from posting here
Oops. I think I owe you an apology. I think that I was the one that first got into which colors salmon see. Your contributions on that topic were useful and informative. I wasn't complaininng about those posts at all. Not a veer IMHO, and definitely not a hijack.
Anything on lure colors and color vision on fish is plenty on topic as far as I am concerned. We don't need to get too uptighht about this.
I have a couple more things that I have learned on color vision in fish that I would like to share before I wrap up what I have on this topic, and any insight you might have would be aprreciated.
And that goes for the rest of you folk as well!
-J
When we talk about lures/visual acuity underwater I know something that has been mentioned in the past (that makes sense to my mind) that the more "accurate" a lure looks, to a certain extent you may actual be hurting your chances since these species have evolved with their appearance being part of their defensive strategy to AVOID being eaten. Then I suddenly had a flashback to something that was all the rage a few years ago - VERY realistic visual stickers of baitfish that guys would paste all over the bottom of their boats - the thinking being that predators just interpret the bottom of your boat as part of a "bait ball". Again, I think that was probably more marketing to fisherman since a true 3D sardine in water is probably going to look considerably different that a 2D sardine that is glued on a boat hull... - john
Hey John, maybe somebody should start a thread on Acuity! 8) /snark
Acuity does have a relationship to color vision- so let's go there.
There are two basic types of light sensor cells in the eye of fish, (and pretty much all other animals).
Rod cells respond to a wider range of light wave frequencies, centered on the higher energy waves that tend to be visible even in low light situations. Rods cells are quite sensitive, meaning that it doesn't take too many photons hitting one to make it fire off.
Cone cells respond to a narrower range of frequencies and are not as sensitive as rod cells.
Now here is the sort of non-intuitive part: Less sensitive receptors actually provide better acuity. By requiring a stronger steady signal, cone cells are less likely to misfire, or fire off on a stray light wave that was a product of random diffusion or uneven refraction. It takes a nice steady stream of light reflecting off a surface.
The primary purpose of cone cells is to provide more accurate images (high acuity) when sufficient light is available. This explains why colorblind fish like tuna have cone cells for just one color, and not just rods. Being able to differentiate colors is secondary to acuity and only possible in species with multiple types of cone cells that respond to different frequency ranges.
AND...
Different species have different evolutionary strategies on the layout of cone vs rod cells. The real estate on the cornea is limited, and every spot that you put a cone cell is a spot that you cannot put a rod cell. Taking available light (including time of day) into consideration, it makes sense any species have optimized to limit the amount of cone cells, and to cluster them in positions where they will do the most good. For groupers, this tends to be straight out in front where the field of vision from the eyes on the side of the head overlap a little. Makes sense for an ambush predator. Tuna are running down prey out in the open, so the cone cells are concentrated in a position to receive light at an angle from in front and above.
That leaves the rod cells. Since the underwater environment is visually compromised, and when the fish are feeding is often not the brightest part of a sunny day, the rod cells play a big roll in finding prey. The fish that sees the prey first gets to eat first, not the fish that sees the prey most clearly.
This leads to another misapplied truism that cracks me up. When you hear that tuna have very good vision, it doesn't actually mean that they have high acuity. Bluefin tuna (especially juveniles) run into the walls of tanks and pens at a rate that makes it an issue for fish farming. Being good at finding prey that is not right in front of your eyeball is a tradeoff that means giving up some acuity. You gotta give up some of one to get more of the other.
I don't want to get too far off topic after harassing some of you folk for doing the same, but I will note that if a bluefin went to the DMV to get a driver's license, it might need glasses to pass the vision test.
If I get enthused again, I can start up a thread on visual acuity and a couple other aspects of tuna and other fish vison, but I am getting kind of burned out at the moment.
Plus the reality is kind of a buzzkill :)
Still some amazing stuff though - don't get me wrong- we just tend to think of the tuna visual system as being some sort of superhero version of human vison. The reality is that it is quite different, and tuned to their environment.
-J
Hey Dave, do you have an explanation for "line shy"? Dominick
I don't see how line shyness is color related. Probably not even about whether or not the fish sees the line. But don't want to drive us too far off topic here. We did talk about this subject in another thread. I'll look for the link.
-J
I don't remember if I mentioned it before, salmonids cones and rods actually move to higher priority depending on the day/night cycle. This is why morning (especially) and evening are prime times to nail salmon.
The Man
Thanks!
There are species whose rod cells move outward between dusk and dawn, giving up some acuity and color vision (cone cell vision taking a back seat) in order to gain some sensitivity. It is a slow process, so it is based on time of day and not a response to current light conditions. Don't know how common this is and I haven't seen a reference stating that salmon do this. I would appreciate a link if you have one.
-J
Let me dig it up,
It was a journal article behind a paywall. I'll download the PDF if I can find it again.
The Man
Here's a link to a webpage. I'll look for the article tonight.
Grey-scales and contrast is that what makes a lure better,,,, ???
I think that I have gone as deep as I want to go here into color vision in fish. So here is my wrap up.
---
How to turn what we know now into into actionable information? Here is one example: On the latest SOA trip, PJ reported that the Mustad Rip Roller in red was the hot bluefin jig. I am presuming at night.
Skipping to just the color aspect of the lure. we know that a bluefin is not going to pick up red as anything other than black, and it is already all black down there at night...
But there does appear to be glow in the dark dots on this jig. Knowing that laternfish are a common prey item for bluefin, and laternfish use rows of bio-luminescent dots for counter-illumination as camouflage, there is an argument that (a) those dots will actually be something visible (even when not fully charged), and (b) there is a plausible reason why they might be an attractant to bluefin.
If I was on this trip and was convinced that this lure was actually doing better than others, for the color part of the selection, I would be choosing a similar jig with glow dots over one that was simply red. I would still care more about the other aspects of the jig.
----
I hope that you folk found this thread useful. I learned some new stuff myself, and sharpened my conclusions by sharing what I have learned. I know that some folks wanted to spread out into related topics, but I think it helped to stick to the narrower topic of color vision. My thanks to those that helped stay the course.
I had intended to start another thread or two on what I found in the scientific literature on some of the other key aspects of fish vision. But I think that I will take a break for awhile. Cat herding can get exhausting, and some of the cats here just like being cats.
-J
Very interesting thread