here's the deal. I'm a fish biologist, and if anyone has something they want to know, I'll either answer it, or tell you where you can find the answer. And if I can't, I'll defer you to Steve H.
-bio...

Biofish- Given many Muskie lakes in WI are not natutally reproducing, doesn't it make sense to stock these with superior non-native WI strains, i.e., to enhance the availability of bigger fish? What's your view of the issue from a fish biologist's perspective?

Thanks EM

It's your choice to Catch'em & Let'em Go!

>< ))))*>

Bio,
Thanks for offering to allow us to pick your brain a little.

There has been a lot of debate lately about the "shallow water digestion" theory. Got any knowledge of fish metabolism, prefered water temps, etc. that might help sway the popular vote one way or the other on this interesting subject?

What's your view on the connection between Oxygen content and fish location and behavior (how active they are)?

What do you feel are the primary senses used by a musky to feed (sight, lateral line (touch), audible sound, smell, or taste)?

Can fish be forage selective? Is there a favored forage in each ecosystem based on availability? If a musky swims up to a rock bar and sees a bullhead, sucker, cisco, perch, and a big old carp all waiting to be eaten... which one would the musky eat first?

Do you feel that having a better understanding of what makes a musky tick can make us better fisherman?

Give me some more time... and I'll think of lots more questions. Lookin' forward to your thoughts on these.

jlong

Other than Ciscos, Tulibee and Whitefish, what other types of baitfish migrate to the shallows in the fall to spawn or for other reasons? Is water temp the deciding factor for these movements or is it something else? If water temp is the reason, then at what water temps do each of these bait fish make this move? What size/age of female muskies make the best spawners for numbers/survival success rates and the potential for trophy size of thier offspring? Why do lakes without Northern Pike tend to have very little trophy potential for muskies? What strategies do you feel are best for increasing the trophy potential for WI waters? Size limits? Slot limits? Bag limits? Strain of fish stocked? etc...

Thanks

Lockjaw

Biofish,

Drop me a line at my email address. I would like to discuss your offer. It would be very helpful to have a Fisheries Biologist to answer some of the questions that come up.

Jim McCullough
Moderator-Muskie Central

Esox Maniac-- Genetics need to be taken into consideration when stocking. Many biologists frown on stocking natural lakes with fish that are not from the same drainage. For example, when stocking walleye in a particular lake, we've only been able to use stocked walleye from a nearby lake. It's a touchy subject, but I personally feel that keeping the genetic integrity of a fishery is more important, than making more lakes into trophy fisheries.

Jlong,
I've been following the shallow water digestion topic for a while. I don't have any first hand knowledge of it, but I know a guy who got his Phd working with Tiger muskies, and I'll try to get ahold of him, and pose the question.

As far as I know sight is the most utilized sense for feeding, but they do have a well developed lateral line, which they will utilize more in more turbid waters. I guess thats why fisherman will use baits with more vibration in those waters.

Fish can absolutely be forage specific. This goes for all species. It relates to something called forage for effort. Example- A musky may key on a food that may be small but that food source is abundant, and the musky doesn't have to spend much energy to capture and consume the prey. It may prefer this to spending more energy in the pursuit of a bigger meal. There will always be exceptions.

And of course having a better understanding of muskies, as with anything else will make you a more efficient angler.

fishbio
what state are you from,,,wouldnt be missouri would it

Lockjaw, small walleye will also be in the shallows (hard substrate) this time of the year. We've seen muskies in the shallows at night, as well as bigger bass, presumably foraging on these smaller walleyes.
Ciscos(tulibee) spawn when temps are between 42-39 degrees. It occurs in substrate free of vegetation in 3-6 ft. Whitefish spawn over gravel or small stones, from 6-30 ft, when temps 40-43 degrees. Female muskies generally reach sexual maturity anywhere between 3-5 years. The number of eggs correlates with size of fish, but larger fish will produce larger eggs. The eggs and young fry are most suseptable to water temp. fluctuations, and that is probably the biggest factor for year classes. As for strategies for increasing trophy potential for muskies, I think the best one would be to look at each lake individually, find out what is the main forage for musky in that lake, and manage the food base.

I'm curious why managing the food base is the best way to produce trophy muskies, assuming that I read your reply correctly.

Food bases can change very rapidly, especially in a lake that sustains several types of forage, do you manage all of them, or just a few. Particular muskies may be forage specific, much like trout can be, but not whole populations. They will adapt to forage changes as they come, so why manage the forage which will be cyclic on it's own year in and year out?

Managing forage is managing the food pyramid from the bottom up, to produce trophy muskies usually a top down method has proven to work the best. The forage doens't matter if the muskie can't make it to trophy size because it got killed at an early age.

John Skarie

What time of year do gizzard shad spawn? And at what water temps?

Bio,
I'm aware that muskies have well developed mechanosensory capabilities (lateral line).... but what about AUDIBLE sound? Do you believe that muskies respond to higher frequencies (audible sound) with the inner ear in a positive way.... or simply the low frequency VIBRATION (from water displacement) that is detected with the lateral line?

That's the technical version of ..... "Do rattles work?".

Second, why would one AUDIBLE SOUND attract a musky (like rattles in a lure) and another trigger an "escape" response (like dropping an empty beer can in the bottom of an aluminum boat). Both are unnatural "sounds".

As far as forage preferences go.... is it more about opportunity or is the baitfish connection more of a LOCATION thing. Will a musky relocate to eat an equal opportunity? If so, wouldn't "matching the hatch" be a better presentation since they are there to target a specific food source? And, if fish will relocate for a preferred forage... why aren't all the muskies in one spot? I can catch fish over open water one minute... and in the slop the next? This would suggest that muskies eat whatever is in their house.

Thanks for you insight!

jlong

Gizzard shad spawn between May and August with water temps between 50-70 degrees.

I didn't mean to imply that managing the food base is the only way. A lot of management strategies incorporate several factors: including size restrictions, and supplemental stocking. The hardest aspect in managing these fisheries are the abiotic factors, and these are often cause the most mortality, especially in eggs and fry.
John, I see you compared trout being forage specific to muskies. Well, that's a good analogy. I've read research that a trout will become habituated to a particular hatch after it sees somewhere around 200 individuals pass over. Then the trout will almost exclusively forage on that particular insect. At least until the hatch is over. The same could be true for muskies. If their in a lake where there is a high abundance of perch, or suckers, they may be habituated to a particular forage. However, I just read a paper that did a study on food habits of Musky, and in 1092 muskies stomachs, they found 31 different species of fish. Like I said, there's always exceptions.

jlong,
The lateral line are hollow scales that are conected across the length of the fish, and then they connect to the ear of the fish. So basically fish 'feel' vibrations in the water, which translate to sound. So it's basically the same thing to a fish.

As for high and low frequency, fight or flight responses: my best guess is that these low frequency 'rattle' sounds put off a similar vibration to a struggling fish. Remember, sound isn't the same thing to fish, they feel hearing- if that makes any sense.

Mr. Fishbio...could you at least give us a first name, I feel rather stupid calling you Fish bio. Since the trout analogy was brought up a question came to mind. I live in Montana and fish the upper Missouri which has enormous hatches and the trout do home in on one or the other very specifically. They even get more picky and may be nailing on the emergers and not the adult flies...gets frustrating at times. BUT, and I wonder if this applies to all fish, I can approach a feeding pod of rainbow and get them to hit a rapala almost every time...that I attribute to "herd" mentality--a reaction strike. But I also can lob a whole, freelined nitecrawler at them and it will get eaten most of the time. This works extremely well on individually feeding fish also...I spot the fish surface feeding and lob the crawler 4 or 5 feet in front and let it drift to they position. Why are they so picky about the flies they are eating and yet gobble the nitecrawler so quickly (granted, not every trout will go for the nitecrawler but I can get many to do so)? Are they really so specific and yet grab a "big" meal opportunistically?

The Nite Crawler Fishing Barbarian,
BrianW

Bio,
I've been studying the lateral line and find it absolutely fascinating. I believe it is why many of our lures actually catch fish (wrote an article on it too).

My next venture is to further understand any relationship audible sound has on fish feeding bahaviour. I beleive muskies can easily "feel" a lure withOUT rattles. My question is, do fish have the capability to determine the location of an AUDIBLE sound source (especially with all the acoustical background noise from boat motors, waves crashing on the shore, etc)? Lateral line feedback provides the fish with datum that can allow the fish to pinpoint its targets location (if the target is within twice the distance of the fish's body length). Can the inner ear of a fish (capable of detecting audible sounds such as rattles) provide similar directional feedback?

The way I interpret the literature is that hearing is a long range sense.... "feeling" with the lateral line is a short range sense. IF (and I stress IF) a fish can determine the direction from which an audible sound originated.... rattles would/could be beneficial to fisherman. Considering my statements, please enlighten me with your view of rattles from a biologist's point of view. Thanks, this is fun!

jlong

Hey there Biofish,
I've got 2 ponds up north each a little over 1/2 acre.I was wondering if you'd be willing to discus some stocking and management questions I have? If you can, we could talk about them off the board since they are not muskie related. I wouldn't want to tick anyone off.
Thanks for your consideration.
Bob
mtjdehhep@aol.com

Where can the average Muskie nut get some good literature to read about Muskie biology and some of these issues, forage, lateral line, etc.? Is there anything available online? I frequently see references by biologists and other authors to "studies" they have seen or "papers" they have read, and I wonder if these are somehow publicly available. Do we just need to show up at the library and start digging? If so, what books/authors would you recommend? Thanks!

I've found Sheryl Coombs and John Montgomery's work on lateral lines to be outstanding. Loyola University in Chicago is an AWESOME resource for fish biology... especially in regard to the lateral lines.

The "Journal of Experimental Biology" has lots of good "papers" available on-line for all to view. Please read them and form your own interpretations of the data.

I have a scientific background, but not in biology. When I discuss these types of subjects... it is based on real evidence, however I make my OWN interpretations of the data. If you read my articles, keep that in mind. Hopefully everyone will acknowledge the information as being credible.

We will always have to make assumptions and interpretations to connect the scientific world to musky fishing. That's why I like it. Tough to prove anything so anyone's THEORY has potential.

Have fun digging through the literature and please share YOUR thoughts as well. Nobody is 100% correct in this field.

jlong

ok, shallow water digestion theory, according to the phd, that got it working with muskies (not me). There is an optimum temperature at which musky metabolize, which is near 20 degrees centegrade. At this water temperature, there would be no need for a musky to 'sunbathe' in shallow water to increase its metabolism. However, if it is being observed that these fish are 'sunbathing' in shallow water, during non-peak temperatures, it would only make sense, IF, fish are also seen sunbathing at the top of the water column, in deep water as well.

I'm not going to give up all the secrets, but...

http://afs.allenpress.com/afsonline/?request=index-html

is the american fisheries society on line journal index,
it covers the journals from:

-Journal of aquatic animal health
-North american Journal of aquaculture
-north american journal of fisheries management
-progressive fish culturist
-transactions of the north american fisheries society

its a little sketchy, but a good start.

doc esox,
you do my heart good. I used to be head fly fishing guide for a fly shop in colorado, I also used to own a fly shop out there, and I can't tell you how good it is to hear that another fly fisherman is not afraid to through some hardware. I could probably answer any trout questions better than the musky ones. But as of yet, I haven't come across any studies that compare trout reactions of plunking night crawlers in front of trout habituated to specific fly hatches, but if I ever do, I promise, you'll be the first to know.-bio..

Bio,

To kind of touch on some of the things jlong was getting at with sounds, do you think that muskies can hear the radio in the boat when we're listening to our NFL games on Sunday afternoons? I can't remember catching one with the game on. (Maybe they don't like football!) I'm sure it probably doesn't have an effect for most of the retrieve. But what about when we're trying to get one to eat at boatside on a figure 8? Think they'd get spooked by the radio? My lack of action with the game on is starting to get me paranoid!

DOUBLE EDGE SWORD,
Guys, I really love doing this. There's a lot of great questions that are being put out there, and I'm doing my best to answer them.
BUT, there are a few things that everyone needs to realize...
Yes, I am a biologist. Yes, I do have a degree in fisheries biology. No, I don't want to give you my name, or let you in on who I work for. I hope you can appreciate this. I'm in a field that's very difficult to get into, and the people that are in it, for the most part, either keep to themselves, or think that the common sportsman is beneith them. I was fortunate enough to find a way into this profession, and now that I'm in, I want to edjucate the public, as well as listen to concerns, and offer what advice I can. My advice, however, is my own, its not the advice of other biologists, or agencies. I do have a ton of resourses available, and I am using this forum to make me use some of those resourses to help make me a better biologist. I used to own a fishing shop in Colorado, and gave it up so I could get my foot in the door of this little world. So, I will always be an angler, I'm just a biologist to help me become a better one.
I do stay pretty busy at work, but I will try to get to everyone's questions. I guess that's why I came into work 6 hours early.

-bio...

lateral line,
bear with me, if you look closely at lateral line scales, they are hollow, they have a little hole in the middle of each scale which is filled with water. Now, sound travels through water 5 x's as fast as it does in air. and sound travels by waves. these waves produce,well waves, in the water. These waves come in contact with the lateral line scales, part of the wave will make it through the little openning, and since the scale is hollow the wave bounces off the inside, and becomes amplified. Now at the interior end of these scales, there is a little hollow tube, that connects all the other lateral line scales and passes all the way along the length of the fish,to the inner ear. Now there are 3-4 bones in the inner ear which are called otiliths. These bones will vibrate, which the fish interprates as sound. If these waves hit one side of the body more than the other, the fish would be able to sense which side the vibrations are coming from.
Now I digress, I read a study a while back where a walleye was placed in a 6 foot long tank, with a minnow that was 'hovering', In absolute darkness, the walleye found, and consumed the minnow.--conclusion, the walleye could find this minnow, and 'feel' the vibrations with the displacement of water caused by only the pectoral fins that the minnow was using. Now I know that walleyes have a more utilized lateral line, but for some reason, that study popped into my head.

I don't think that fish can hear the radio. I read somewhere sometime that someone did an experiment through the ice with a hand auger, a gas auger, and a spike. there was a diver who took sound measurements from under the ice, and found very similar sound measurements between the gas and hand auger, but the most sound transmitted through the ice with the spike. So for that reason, I don't believe that listening to the radio would do you any harm, but stomping around in an aluminum boat would.-bio..

Biofish,
Do you think a fish can differentiate an AUDIBLE SOUND from a high energy source versus a pressure pulse from a low energy source such as displaced water? The frequencies are much different and may or may not be detected by the lateral line (low freqency sensitive) vs. inner ear (high frequency sensitive).

Your example of the walleye locating and eating a minnow in a dark tank demonstrates the capabilities (and sensitivity) of the LATERAL LINE to detect DISPLACED WATER. John G. New and Lisa Fewkes published a great paper entitled "Strike Feeding Behaviour in the Muskellunge: contributions of the lateral line and visual sensory systems" which really further supports your example. However, my questions are directed towards audible sound.

Take a depthraider for example. One with and one without rattles. They both move through (displace) the water in the same manner, however the one with rattles also "emits" a higher frequency wave that can be detected by the inner ear. I want to learn more about how a fish perceives the higher frequency sounds that WE can hear to help determine if rattles are good or bad.

Since a fish can hear the rattle BEFORE it can FEEL the presence of your lure.... I want to know if the rattle "prepares" the fish for the approaching lure in a positive way or if it MAY actually trigger an "escape" or "fleeing" response... which would be bad. I've caught many fish on lures with rattles... but I often wonder if those fish would have taken that lure even if it did NOT have rattles. What do you think?

jlong

Would a slot size limit help or work on some lakes in wisconsin for musky. Have seen it work for walleye and bass, why not muskie.
Don Pfeiffer

-slots for musky- Well, to my knowlegde, its never been researched. But let's think about it.. Why are slot limits implemented?. 1. To allow a fishery to keep those fish with the highest reproductive potential in a system, while still allowing angler to have an opportunity to harvest a trophy. I Think that makes good sense. But muskies are considered a low density fish, and the adults are the top predators in the system. Leaving more, and larger of the top predators in a system will place added stress on the prey base. A musky needs to eat approx. 6% of its body weight per day. ( now that could be a 2 IB sucker every week, or any number of mix and match forage)Managers would have to look at the prey base in the lake, and decide whether the system would be able to survive. For example, Colorado public wanted to make its reservoir fisheries into the trophy lake trout fisheries like those in Utah. So the division of wildlife set higher minimum length requirements, and the Lake trout got bigger, but the prey base crashed. They are stocking the reservoirs now with kokanee salmon, just to feed the lake trout. They are at the point where they are ready to let the lake trout crash, so they can start over again. Now natural lakes have much more diverse food chains, but my point is, that unless the fishery can handle the extra strain of having more top predators in the system, than we might be stocking walleyes for musky food. (not that too many folks on this web site would mind:)

Biofish/JLong- Very interesting dialog. Lateral line is fascinating, i.e., actual mechanism. Net result it gives the fish the equivalent to human hearing. Close your eye's & you can locate/turn toward the source. This would seem to be a big advantage in sensing potential prey as well as predator sensing. Especially true for turbid water and/or low light levels. Therefore development of the walleye lateral line is no suprise. I wonder if the Muskie's lateral line is better than the Northern Pike's. I've never heard of Pike caught at night. What about the pores under the jaw, Muskies have ~ 7 whereas pike have 5 or less per side. Thats almost a 30% increase. Not having gotten into Esox biology before. Do these have any function with respect to prey sensing? Is there also a similar difference in their lateral lines, i.e number of sensors?

Interesting article in the July 1984 Scientific American "Form & Function in Fish Swimming"; by Paul W. Webb (Professor at University of Michigan).

As with all things in the natural world, form & function are intertwined. The Esox family is especially suited to quick acceleration. Most of us have been firsthand witness's as to how fast these fish can accelerate to smash a lure. However, the Esox shape & profile also appears to aid the fish from detection by its prey, i.e., predator avoidance reaction by the prey when the predator strikes. The smaller predator strike profile probably minimises the stimulation of the prey's lateral system. Maybe this explains why "the sucker get's nervous", but it can't avoid the Muskie. Great stuff!

"It's your choice to Catch'em & Let'em Go"!

>< ))))*>

Biofish, I was wondering if there is anything about muskies schooling up together? It seems to me that sometimes on the lakes I fish they kindof pack up, maybe to try to confuse prey, like wolves. Do you think I might be on to something?
Thanks, Dave

Fish Bio,
A ? on the great lakes strain of muskies (Erie). I was told that they migrate with the bait fish. Any truth to this?

Thanks,
CPR <*{{{><
Matt and Judy

Dave,
All game fish school.
In my experience we have caught #'s of muskies off the same spot on consecutive casts or on consecutive trolling passes.

fish bio,

#1 At what point do you feel the muskies scatter, meaning sense we know they school at what point do the spread out? The lm. bass scatters at the weedline but I'm sure about the muskie and I have experienced them scattering at the base breaklines?

#2 How many muskies have you caught?

#3 At what depth do you feel the muskie take's up sanctuary, under normal weather conditions with water clarity weeds growing out to 12-13'?

#4 How many times on a normal fishing day do muskies get active?

Now that you have returned could you give us your opinion to the above questions.