Striped bass: Sense of vision, Vision ability

[buckethead]

Any thoughts about striped bass vision and ability to see different colors in different water clarity?
I have found chartreuse and white seem to be 2 of the best colors when clarity is iffy.
Yellow can be good as well.

[plugginpete]

I like chartreuse when the water is dirty or for big surf.

[rip316]

If it ain't chartruese its no use!

[surfstix1963]

What ^^^ he said.

[Pebbles]

I like pink because I'm a girl!:)

[DarkSkies]

Some people and I have had discussions about bass and their ability to see relative to time of day. A lot of the old timers have said the end of day bite sometimes dies, unless it's a blitz, and bass are keyed in on a feeding frenzy with bait. This will over-ride the natural transition period from the day to the night, or the night to the day.

To me, the period from the day to the night seems more pronounced, where it seems that bass need at least an hour or more for their optical receptors to adjust to the light change.

That's why some guys believe the first hour of darkness is the time to leave the beach for a coffee, bathroom break, grab a bite to eat, hit the tackle shop to load up on supplies, etc. They feel this first hour is often non-productive. For the most part, I tend to agree with them.

I wonder if members here have asked themselves that same question, and wanted to know "why" in a scientific sense.

*************

Here's a great article penned by Dr NEKF of the new England Kayak fishing site. After reading it, why not take a visit to his site as well? :fishing: He has a host of interesting topics and fishing/kayaking subjects he discusses. :thumbsup:
http://www.newenglandkayakfishing.com/content/articles/54-striped-bass-anatomy-and-fishing.html


Written by Dr. NEKF Wednesday, 19 December 2007 19:00 By Dr. NEKF


Knowing about the fish you are going after can help improve your odds as a fisherman.

The nervous system of the striper, Morone or Roccus saxitilis, consists of a forebrain, midbrain, brain stem, spinal cord, and nerves. It operates mostly on instinct that is programmed into its nervous system. In addition the nervous system and organism as a whole operates on a reflex basis depending on environmental stimuli. The brain has a very small cortex, therefore it does not have advanced capabilities for memory and emotions as we know them.

Vision in a striped bass is not as keen as its other senses and is used mostly for short range encounters. However, its retina contains an ample population of rod receptors and some cone receptors allowing vision to be similar to ours.
The rod receptors enable the fish to see in low light conditions whereas the cones allow color vision. The eyes are large and are set slightly forward and upward on the head. This enables some binocular vision and facilitates looking up at its prey from below. The lens is round and does not flatten to focus light on the retina like our eyes. However, the lens can be moved closer to or further away from the retina to focus an image. Fish also do not have eyelids because their eyes are constantly in water and won’t dry out. Six small muscles very similar to ours control movement of the eyeball.
Because of its large eyeball size and density of rod receptors on its retina, a striper’s visual system allows it to be an excellent nocturnal hunter.

Striped bass have a wide color visual range, especially during daylight. A recent study from the Virginia Institute of Marine Science (1) has shown that stripers are sensitive to a large part of the color spectrum and their retina is sensitive to very rapid movements. The middle of their spectrum sensitivity is yellow and yellow green. This means their peak response was to the color yellow. Is it any wonder that chartreuse colored lures work well? According to VIMS researcher Andrij Horodysky, "Nothing in the wild is ever chartreuse, but the color is right smack dab in the middle of a striper's visual range. They can see it really well."

Researchers also found that during daylight hours the retinas of striped bass, as compared to weakfish, respond much better to light of red wavelengths yet both fish do not respond to red wavelengths at night. Another fascinating fact is that the rods and cones, the two sensory nerve cells of the retina, actually migrate and change position on the retina in accordance with day and night. This circadian rhythm also changes to adapt to seasonal differences. During the daylight hours, cones migrate to the surface of the retina to allow color vision and acuity while the rods take a back seat, literally.
During the waning hours of light and nighttime, the reverse happens with the greater density of rods affording low light vision and contrast discrimination.

In a camera, shutter speed is the speed at which light is allowed through an aperture setting. In fish, this speed is called “flicker fusion frequency” and is measured by a technique used in humans called electroretinography. Essentially, the amplitude and frequency of nerve impulses from the retina are measured in response to stimulation inputs. In striped bass, their “shutter speed” is fairly rapid, measuring around 50 cycles per second, almost as fast as humans (about 60 cps). This enables them to see large and fast moving prey similar to menhaden. This is in contrast to weakfish with a fusion frequency half that of the striper: 25 cps. In addition, weakfish have a visual spectrum that is optimal at lower wavelengths when compared to bass. These two factors allow weakfish to see contrast better than color and slower moving prey. This enables them to see in low light conditions and small prey that inhabit the night such as shrimp and small fish. In addition, being more sensitive to the lower end of the light spectrum, weakfish can see in ultraviolet.

For fish to see optimally, water clarity is essential. Murky waters force fish to use senses other than vision and can account for the disparity found in research of the stomach contents of stripers. Due to their visual capabilities, you would expect to see a preponderance of large fast swimming forage in their stomach. Quite the contrary was found in murky waters as their bellies were filled with juvenile crustaceans and shrimp. It seems that in turbid waters, stripers are forced to feed in contrast to the evolutionary development of their visual system. Researchers are now raising different questions: Is it the prey per meter amount or the number of prey they are able to see in our bays that is important for survival of these visual predators? If they can’t see their prey ideally, how can they optimally eat it?

M. Saxitilis does not have external ears, yet it has an exquisite capacity to hear sounds, especially since sound travels faster in water (3200 mph) than in air (769 mph at sea level, at 70 degrees F). That’s about 4600 feet per second, faster than the muzzle velocity of most high-powered rifle cartridges. Stripers, like most fish, use the lateral line system to sense vibration and movement. They have internal ears that detect sound and transmit information as to spatial orientation and balance. Therefore they can sense water current, other fish, prey, and other objects, including lures that make noise and vibrational sounds.

The body of a striped bass displays power and strength. It’s large tail and muscular body enables it to stem strong currents or swim quickly for shorts bursts. However, it also means that is must eat to sustain strength and stamina. Therefore it is no secret that M. saxitilis has a voracious appetite. In addition, its large size means a large amount of muscle mass. When a muscle contracts and exerts energy, it generates an “oxygen debt” and an overproduction of lactic acid. This can change the pH of tissues and cause damage to muscle cells. Metabolic changes can even usher in death. In addition, variations in the fish’s environment can alter stress-related death. High water temperatures (as in the summer months), lower salinity, and decreased oxygen saturation can adversely effect a fish's survival due to the stress of being caught. In striped bass, temperature, salinity, and fish size have been shown to be the three most important factors affecting survival in catch-and-release programs. Larger fish engage an angler longer and are harder to handle. A larger fish also has a greater ratio of body mass to gill surface area and therefore has a more difficult time paying back its “oxygen debt” incurred during a fight. In other words, it can’t efficiently get rid of carbon dioxide generated via muscular exertion and re-oxygenate tissues fast enough.

This can result in deadly metabolic changes. The weight of their bodies out of water can cause injury to their vital organs if held improperly. Larger fish also tend to swallow bait resulting in getting deeply hooked, a potentially lethal situation. The odds of a striped bass dying are more than 15 times if it is deeply hooked (gut)! Lastly, exposing a fish to air, especially if it is warm, will increase their stress-related mortality.

Each time I successfully release a striper I am reminded of what the famed fly fisherman Lee Wulff wrote in 1938; "A good gamefish is too valuable to be caught only once". Follow sound catch and release guidelines and protect our precious resource. Happy fishing and good luck!

Best regards,

Dr. NEKF

[cowherder]

Striped bass have a wide color visual range, especially during daylight. A recent study from the Virginia Institute of Marine Science (1) has shown that stripers are sensitive to a large part of the color spectrum and their retina is sensitive to very rapid movements. The middle of their spectrum sensitivity is yellow and yellow green. This means their peak response was to the color yellow. Is it any wonder that chartreuse colored lures work well? According to VIMS researcher Andrij Horodysky, "Nothing in the wild is ever chartreuse, but the color is right smack dab in the middle of a striper's visual range. They can see it really well."



Thank you for that, Dark. Yellow has been my favorite for bombers and pencil poppers because it seems I have done well on them. Now I understand why.

[surfstix1963]

The old light spectrum remembered that from chemistry, ROYGBIV=Red,Orange,Yellow,Green,Blue ,Indigo and Violet and thats exactly the order these colors are lost over different depths of water and not seen as well.I think I put up a post awhile ago about the colors and depths they range in.

[surfstix1963]

Heres some notes taken from another site I held onto awhile back.When you combine all the colors of the light spectrum their resultant color is pure white light.(and this is why I believe white will and does work at night as well as during the day.)

ROYGBIV=Your very basic color wheel.R+0=Y+G=B+I=V

@10 ft. the color red is not seen well, orange is almost gone and yellow is starting to fade

@35 ft.Orange is no longer seen & yellow is rapidly disappearing.

@75 ft. the color yellow starts to turn to a greenish-blue color(see the pattern here Yellow and Green=Blue) @ this depth the only visible colors are blue,indigo and violet.

@150 ft. blue and indigo are very hard to see and violet is disappearing.

@ approx. 200 ft. violet is gone and the only light is ultraviolet which is undetectable to even the human eye.

The more cones and receptors fish have in their eyes the more colors are available to their sight(actually I think it is the contrast of the color not really color itself reflecting against the sky and back to the water so naturally their sight is better.
Bass will use their other senses to lock onto prey and use sight as the last minute attack mode.
Catfish only see things as grayish black because of the lack of multiple cones and receptors.

I don't think too much of this applies to a surfrat because we generally are not fishing in water over 35 ft. to often,unless dragging a tin you may want to keep an eye on tailhook color or tube color it may help:don't know why:white will generally never leave you down it is the all around best color to start with in dirty or clean water it is a neutral color. Just my .02 cents:huh:

[jonthepain]

good article dark, thanks

looks like i'll be trying out that new chartreuse clouser surfstix sent me.

great looking teasers! thanks again!

[surfstix1963]

Your Welcome Jon.

[DarkSkies]

good article dark, thanks

looks like i'll be trying out that new chartreuse clouser surfstix sent me.

great looking teasers! thanks again!

Don't mean to hijack this thread guys, but right now we have back bay bass dialed in to the grass shrimp bite. Fly guys have been hitting double digit catches of bass to 36" at night using grass shrimp imitations.

Surfstix was so generous when he sent Pebbles and I our custom Surfstix ML swimmers that I failed to notice some of the "extras" he stuffed in there.

Last night I was looking to make some kind of casting egg setup and was pawing through the flies/teasers I have for the perfect grass shrimp profile. I found out I didn't need to match the "profile" as surfstix makes these awesome grass shrimp flies. :drool:

I set them all up with the eggs, and some other wacky rigging, Dr Frankenstein style. :eek:

Didn't fish them just yet, got sidetracked watching bass feed in the ocean this morning. :dribble:

I'll report back on them when I do.
For now I just wanna say "thanks!" Surfstix, those flies are perfect.
They look just like grass shrimp, carbon copies. :thumbsup::thumbsup: :drool:

[surfstix1963]

anytime Richgo get em hopefully they work out for you.

[stormchaser]

Good thread. I like yellow and black.

[DarkSkies]

white will generally never leave you down it is the all around best color to start with in dirty or clean water it is a neutral color. Just my .02 cents:huh:

Just noticed your comments here surfstix. Lots of dirty water right now.
Right on the $$, thanks. :HappyWave:

[Rip-Plugger]

thats a great post Rich,I read something like it a few years ago at a college website and it said the same thing,,that chartreuse was dead center of it's color vision.
in my experience it is first light or right before that the best action starts,,5:00-am till about 8am.
seems that right before it starts to get light the bass load their pistols and are cocked for feeding.another thing is the choppers seem to show their teeth at the same time.if it's a gloomy morning,it's my fave morning,bass will hit till they want to move on,gators too.love them gloomy,dark,dry am's

dusk is another thing around here.bass don't hit too much before dark,when it gets dark then they start.
gators show up anytime during the change of light conditions or after.
the bass don't seem to be in the spot they are at first light,they are in staging areas instead and very willing to crush anything coming past their window.
the rips i am thinking of always have a few bass in them at some depth/distance from shore,,,,thats why I like to drift a large plug waay out and drag it back through the entire rip,it comes by them at some point.

these 3 are but a small cross section of the fish I caught out of this very long rip I speak of.

R-P158161581715818

[clamchucker]

An interesting article on fish vision
http://www.vims.edu/_docs/fish_vision82.pdf


Horodysky Throws Light on Fish Vision

Andrij Horodysky’s research can besummed up in a simple saying—what you see is what you get.Horodysky, a VIMS graduate student working with faculty members Drs. Rich Brill, Rob Latour, and JackMusick, is using electroretinography—a technique first developed for studying human vision—to explore how fishes see the underwater world of ChesapeakeBay.

Brill, an internationally recognized fish physiologist who heads NOAA’sCooperative Marine Education andResearch (CMER) program at VIMS, has recently turned his attention to the sensory world of fish and other marine organisms.

The research is part of an emerging field called “visual ecology” thatpromises to throw new light on animal behavior and the interactions between predators and prey. Horodysky and hisadvisors are pioneers in applying thisfield to Bay fishes.

The researchers are focusing the irinitial studies on recreationally important Bay species such as striped bass,weakfish, croaker, and drum.

This reflects the source of their funding, which comes from the Recreational Fishing Advisory Board of the Virginia Marine Resources Commission. The Board uses money from Virginia’s saltwater fishing license to fund projects that improve the Commonwealth’s recreational fisheries.

Horodysky also benefitsnfrom collaborations with Charterncaptains like Steve Wray,who provide him with the fishnhe needs for his experiments. Horodysky’s preliminaryresults provide basic insight into how Bay fishes see the world. The results show that some species, like striped bass,are adapted to see large, swiftly moving prey in daylight. Others,blike weakfish, are adaptedbto see small, sluggish prey at night.

He is also comparing the types of prey that fishes are adapted to see with the pre yitems that are actually in their stomachs— with some surprising results that could hold important implications for fisheries management in coastal waters.

Electroretinography involves exposing the eye of ananaesthetized fish to all the colors of the rainbow and more—from ultraviolet to infrared— and then using electrodes to record which wavelengths elicit a response on the fish’s retina. Horodysky conducts these tests night and day to account for rhythmic changes in the structure of the fish’s eye.
Even though Horodysky keeps his fishes in a dark laboratory, the rod and cone cells in the fishes’ eyes still shift position in concert with sunrise and sunset.

The color-sensitive cone cells move toward the surface of the retina during daylight hours, and retreat to make room for the contrast-sensitive rodcells at night.

This “circadian rhythm”changes with the seasons, which makesf or some late nights for Horodysky during summer, when he is not able to start his dim-light experiments until 8 or 9 inthe evening.
“The end result of these experiments,”says Horodysky, “is the ability to unambiguously ask the retina whether it can see a particular color, and whether it can resolve the color in bright or dimlight.”

He also tests the fish’s “flicker fusion frequency,” essentially the shutter speedof its eye. Humans have relatively “fast”vision and can discern the flickering of a light or image at up to 60 cycles persecond (that’s why TV screens, fluorescentlights, and computer monitors are designed to flicker at a rate faster than this threshold).

Values in marine fish range from around 25 in swordfish,which require a “slow shutter speed” to detect prey in the deep, dark waters where they spend their days, to around 55 for mahi-mahi, which often hunt at the surface in the sunlit tropics.

Horodysky’s research shows thatstriped bass are most sensitive during daylight hours to a wide range of colors from blue to red, with a peak at chartreuse.

They have a flicker fusion frequency of around 50, relatively fast for a fish, which allows them to track large, quick-moving prey like menhaden.
Compared to striped bass, weakfish have slow vision (around 25 cycles persecond) and are more sensitive to contrast than color.

This allows them to see best under dim conditions, just right for detecting the small fish and shrimp that prowl the nighttime Bay. They also have the unusual ability to see in ultraviolet.

Seeing in ultraviolet is a dangerousproposition, says Brill, as UV light is very damaging to cells and even DNA. Using UV light allows weakfish to distinguish between dark and light objects in dim conditions, but forces them, likebats and owls, to avoid bright sunlight.

“There’s no such thing as a freel unch,” says Brill. “You can have a really good UV-sensitive eye, but then you have to work at night.”
“Even though these two predatorsmay swim side-by-side, they exist in different
visual worlds,” adds Horodysky

[clamchucker]

continued


Fish Vision continued from page 3

You've got two animals that are competing for the same food. How do they do it?

Stripers use color to see and feed during the day.

Weakfish use contrast sensitivity to see at night.

What these fishes have done is divvy up the visual world, says Brill.

For the most part, study of stomach contents by VIMS researchers confirms what Horodysky's vision research predicts.
Work by Dr. Rob Latour shows that the stomachs of weakfish are largely empty during the day, and then quickly begin to fill with small fishes and shrimp as evening falls.

Work by graduate student Kathleen McNamee shows that striped bass have full stomachs during daylight hours, but that the stomachs gradually empty through the night.

One intriguing aspect of Horodysky's research is the disparity he's found between the prey items that striped bass are adapted to see - large,fast-moving fish like menhaden - and the items that actually occur in their stomachs mostly small crustaceans like juvenile blue crabs and mysid shrimp.

Horodysky and his faculty advisors hypothesize that striped bass are living in a visual world very different from the one evolution prepared them for. That's because human activities in the Bay watershed and the demise of the native oyster have dramatically reduced the clarity of Bay waters.

The world of Chesapeake Bay stripers was once bright and colorful.
Anecdotal evidence from Captain John Smith and others suggests that visibility in the Bay once measured in the tens of feet.

Even a century ago, Bay waters were clear enough to allow plant growth at depths of more than nine feet. Now sunlight penetrates to only half that depth.

Chesapeake Bay used to be veryclear, says Brill.
Now we?ve made it mucky. So we see the visual ecology of the Bay changing.

Our argument is that over evolutionary time these fish have made certain visual choices, then suddenly find themselves in a visual environment they didn't evolve in.

This visual mismatch could have important implications for fisheries managers, who traditionally make management decisions based on the relative abundance of predator and prey - the number of striped bass or menhaden netted per unit area.

What we're getting at, says Horodysky,is that it isn't the number of prey per meter that's most important to these visual predators.

It's the number they can see. Is there a visual issue, with the Bay being turbid, being murky?
If yon can't see very far, how is that affecting your ability to feed?

These are largerquestions we can begin to chip away at once we get our baseline data. We can't start to answer these questions until we know the limits of the eye.

In the meantime, Brill and Horodysky plan to expand their research to other popular recreational fish like summer flounder and cobia, and also to the forage fish most notably menhaden that so many recreational species depend on for food.

For Virginia's anglers, the most important question for Horodysky might be how a better understanding of fish vision can give them better luck on the water. "I can't guarantee that anyone who uses these data is going to catch more fish," responds Horodysky. "But they will beable to make more informed choices."

Horodysky, himself a fly-tier and avid angler, notes that his color research does confirm at least one common saying that Bay anglers use when selecting a lure for striped bass:
"If it ain't chartreuse, it ain't no use."

"Nothing in the wild is ever chartreuse,"says Horodysky, "but the color is right smack dab in the middle of a striper's visual range. They can see it really well."

[dogfish]

good read clamchucker thanks

[clamchucker]

You are quite welcome dogfish.

[hookedonbass]

This was a great read. Thanks so much for sharing that.