Blind Bass

[MyKeyBe]

Now, how might a blind bass accomplish this?? The part of the lateral line system...

There you have it. They use their lateral line to feed.

In the book Largemouth Bass by Don Oster they mention a study being done on blindfolded bass.

"In one experiment, researchers placed small cups over the eyes of bass, then dropped minnows into a tank with the largemouths. Eventually the bass ate each minnow, using their lateral lines to locate the baitfish."

[Chris]

Bass in clear water are sight feeders bass in lakes that are always muddy are not sight feeders and rely on their other senses to feed. if you take a clear water bass that is a sight feeder and dump it in a muddy lake it will take a few days for it to adjust and will become less of a sight feeder and use more of its senses. Bass that are blind isn't much different than the bass in muddy water. Muddy water fish in bodies of water that are always muddy are easier to catch than clear water bass because the muddy water hides mistakes. These bass are also less spooky and you can fish closer to them. if your fishing a lake that is normally clear and then becomes muddy those fish are going to be spooky and are going to take time for it to adjust to the water but after they do they become easier to catch.

[Paul Roberts]

Blind Female doesn't get the hint. Or...a blind bass goes a-spawning

I got to see this bass a few times again this spring. She appeared on three of the four shorelines on the pond.

I watched her interact with several bass, a large bluegill, and me. She is aware of what's going on around her but I couldn't determine how well she could see. When a fish approached her she'd turn slightly toward it when the approaching fish was about 18 away. It appears both sound and water movement were at work. When a fish turned away from her and pushed water toward her, she'd turn slightly away responding to the slight jet of water coming at her.

At one point I saw her cruising a shoreline and it appeared she could hear me on the bank above her (20feet away). So I got out ahead of her direction of travel and waited. When she appeared I waved my arms and she turned out, but I realized I'd moved my feet on the bank so I tried again. This time I held my feet still and waved my arms above me and she came in straight at me and ended up right below me.

Like other females that aren't already paired at the start of the spawn, she cruised close to the shorelines looking for males. I watched her at two bed sites.

One already had a line up of four females ahead of her, three better than 18 inches. (She being about 14+"). She felt the presence of one big female and backed into a pondweed clump, and held there.

At the second bed, the male had already received his eggs and, like other males in similar state, fended her off. The odd thing about her was that she couldn't receive the visual cues that said, "Back Off!"

I watched as she approached the bed, and saw the male spy her coming at about 12 feet out. He left the bed to meet her face to face, flared his jaws, and she didn't bolt. So he tried again, and she just ducked to the bottom (like a bullhead again LOL). So the male attacked, flaring and biting at her, driving her into the bottom until a cloud of silt obscured them. He returned to his bed, and I stepped down closer to see if she was still there and she bolted out into the milfoil and wriggled in like a bullhead.

Oh yes, one more thing that might indicate her vision ability: She's a dark sooty black in color. All the other bass are much paler in color with various markings (which I cannot fully decipher the reasons for yet). I seem to remember research out there that indicated blinded fish could not adjust their coloration to their surrounds. This appears to be the case with this bass.

That said, studies show that completely "blinded" bass suffer a 20% reduction in their ability to feed successfully in controlled conditions, probably greater in the wild, and would therefore suffer a competitive disadvantage which could prove fatal in some scenarios.

Brian, that's true, but there is likely a difference between bass blinded in the lab and those that gradually become so. I'd certainly expect compromised vision (and body coloration) to be a disadvantage, however it appears that this particular fish, and a few others I've seen do OK.

Neat stuff to wonder about.

[Paul Roberts]

Update.

I had conversed with Ralph Manns about this fish and he suggested this bass had a nematode worm that sometimes infects fish. He doubted this fish was entirely blind, esp with such fine body condition.

I believe I might have seen her again late last fall, come to a jerkbait. I am not certain, but I thought I saw the clouded eyes on that fish. She moved for the jerk, aborted, and did not come again. Hope I catch her this year; I'd love to inspect her in hand.

[BassThumb]

Very cool!  Thanks for getting the pic and sharing.   8-)

[SuskyDude]

Paul,

Two years ago I caught a very healthy, chunky, 16 inch smallmouth that for all intents and purposes was completely blind. One eye was severely damaged (couldn't have been usable), and the other was completely gone.

Had no problem chasing down a crankbait.

[Paul Roberts]

Thanks Susky. Interesting. I felt the above bass was pretty much blind, and I got to observe her a number of times in different situations. Her vision was definitely very much compromised, but she was in beautiful condition. How she fed exactly I would love to know.

[Bass_Akwards]

So interesting because it makes me wonder how typical this really is for a bass.   I'd think it's almost if not completely impossible for a bass to be BORN blind and survive.  Yet once a bass reaches a certain age, it's superior survival skills and instinct can keep it alive and otherwise healthy. It really is cool. 

I wonder, of all the bass who go blind, what percentage have the genitic makeup and survival instinct to stay alive over a relatively long period of time. 

I'd think that the parents of the bass Paul photographed had to have an amazing genitic makeup and gene pool.  When a trophy type bass spawns, there seems to be a better chance that the offspring will be better adapted genetcally to their environment due to the survival instincts and longevity passed on by it's parents.

The particular year class of the bass Paul photographed very well might be an amazing year class of bass, especially depending on what kinds of conditions the parents had to withstand the years prior to the birth of the bass in Pauls photo. 

Cool picture Paul and good post.  It really gets me wondering about lots of stuff, especially how typical it really is for a bass to survive with this kind of handicap.

[Matt Fly]

Most humans will get them, its called aging. I'm no longer 20-20 without glasses, but still see just fine with reading glasses for short distances.

I never needed glasses until I got into my 40's. I asked the Opthamalogist why, he said, your not as young as you once was. pretty simple and straight forward.

   Raul did a nice write up a few years back on how a bass see's and adjusts his eyesight.      

     I'd like to hear Raul's take on how cataracts effect rods and cones.

[brushhoggin]

Paul,

Two years ago I caught a very healthy, chunky, 16 inch smallmouth that for all intents and purposes was completely blind. One eye was severely damaged (couldn't have been usable), and the other was completely gone.

Had no problem chasing down a crankbait.

"Largemouth bass posses sense of mechanoreception that is kind of like a cross between hearing and touch. The organ responsible for this is the neuromast, a cluster of hair cells which have their hairs linked in a glob of jelly known as 'cupala'. All fish posses free neuromasts, which come in contact directly with the water. Most fish have a series of neuromasts not in direct contact with the water. These are arranged linearly and form the fishes lateral lines. A free neuromast gives the bass directional input.  The lateral line receives signals stimulated in a sequence, and gives the bass much more information (feeling the other fish around it for polarized schooling, and short-range prey detection 'the sense of distant touch)."

  seems like bass' ability to detect prey is similar to bats, only they dont have active electroreception (sensing its surrounding environment by generating electric fields and detecting distortions in these fields using electroreceptor organs) but passive electroreception, which just means they only receive

bioelectric fields. I've seen videos of people feeding their bass in an aquarium and they drop the shad or prey behind them where they, in one motion, turn and suck that prey in as if they  knew exactly where it was without seeing it. i'd imagine these abilities are heightened when eyesight is lost.

[Paul Roberts]

This seems to be a learned ability as well. There's a classic study in which bass were blinded and then fed, and they were severely compromised. Clear water bass that have to live through periods of heavy murk can get really thin -I've seen this.

But from this, and the other thread, it seems it's not rare for sight compromised bass to survive, and even prosper.

[RoLo]

Largemouth bass posses sense of mechanoreception that is kind of like a cross between hearing and touch. The organ responsible for this is the neuromast, a cluster of hair cells which have their hairs linked in a glob of jelly known as 'cupala'. All fish posses free neuromasts, which come in contact directly with the water. Most fish have a series of neuromasts not in direct contact with the water. These are arranged linearly and form the fishes lateral lines. A free neuromast gives the bass directional input. The lateral line receives signals stimulated in a sequence, and gives the bass much more information (feeling the other fish around it for polarized schooling, and short-range prey detection 'the sense of distant touch)."

seems like bass' ability to detect prey is similar to bats, only they dont have active electroreception (sensing its surrounding environment by generating electric fields and detecting distortions in these fields using electroreceptor organs) but passive electroreception, which just means they only receive

bioelectric fields. I've seen videos of people feeding their bass in an aquarium and they drop the shad or prey behind them where they, in one motion, turn and suck that prey in as if they knew exactly where it was without seeing it. i'd imagine these abilities are heightened when eyesight is lost.

This addresses something I often think about, that fish (and other animals)

seem to possess a sixth sense or other tracking device that we may know little or nothing about.

Bass do not have ear holes (auriculars) but have evolved 'internal ears' instead.

Unlike air, which is highly compressible, bass live in a medium that is highly incompressible (water).

For this reason, sound waves travel 'through' the fish's entire body. It stands to reason

that the lateral lines of bass (median lines) would serve to detect low-frequency vibration.

Low-frequency waves are most effective at close range, because they dissipate sooner

than high-frequency waves. Accordingly, it's widely accepted that the lateral sensors of fry fish

are what enable them to remain in a unitized school even in muddy water.

Bass living in water of average clarity, tend to lose bodyweight if the water becomes muddy

(adaptive lag). On the other hand, I've observed bass living in Carnegie Lake, NJ,

which is perennially muddy water, that display average if not slightly above average girth-to-length ratio.

Remarkably, we've caught many bass in Carnegie Lake on soft plastic lures with no clacker or rattlebox,

which strongly suggests that bass are able to perceive and track microwaves, as it were.

Roger

[brushhoggin]

now, who's gonna put out a pulsing crankbait ;D

[Paul Roberts]

lol, that's the problem with lures -they're all made of plastic, wood, and metal.

[SuskyDude]

Paul,

Two years ago I caught a very healthy, chunky, 16 inch smallmouth that for all intents and purposes was completely blind. One eye was severely damaged (couldn't have been usable), and the other was completely gone.

Had no problem chasing down a crankbait.

"Largemouth bass posses sense of mechanoreception that is kind of like a cross between hearing and touch. The organ responsible for this is the neuromast, a cluster of hair cells which have their hairs linked in a glob of jelly known as 'cupala'. All fish posses free neuromasts, which come in contact directly with the water. Most fish have a series of neuromasts not in direct contact with the water. These are arranged linearly and form the fishes lateral lines. A free neuromast gives the bass directional input. The lateral line receives signals stimulated in a sequence, and gives the bass much more information (feeling the other fish around it for polarized schooling, and short-range prey detection 'the sense of distant touch)."

seems like bass' ability to detect prey is similar to bats, only they dont have active electroreception (sensing its surrounding environment by generating electric fields and detecting distortions in these fields using electroreceptor organs) but passive electroreception, which just means they only receive

bioelectric fields. I've seen videos of people feeding their bass in an aquarium and they drop the shad or prey behind them where they, in one motion, turn and suck that prey in as if they knew exactly where it was without seeing it. i'd imagine these abilities are heightened when eyesight is lost.

Yep. And I imagine their sense of hearing is enhanced as well.

But it's still remarkable to me that a blind bass could thrive. The particular bass I was speaking of was not only a successful hunter, but it also managed to avoid the pike, musky and catfish that prowl the river.

Neat stuff.