Observation on Feed Fed Largemouth Bass

Posted by: Jim Wetzel

Observation on Feed Fed Largemouth Bass - 10/23/18 12:50 PM

We are doing an experiment on Largemouth Bass and Spotted Bass where we are pushing them to large size using a commercial diet. Something that is popping out quickly between those getting feed and those eating forage is coloration. I am liking the looks of the forage fed fish over the feed fed even though the latter are growing much faster.
Posted by: Quarter Acre

Re: Observation on Feed Fed Largemouth Bass - 10/23/18 02:24 PM

I always had better aquarium fish coloration when I used the Tetramin brand fish food compared to the cheaper stuff. I wonder if the aquarium fish foods are loaded with extra magic ingredients because color is much more important in the tropical fish hobby?
Posted by: Jim Wetzel

Re: Observation on Feed Fed Largemouth Bass - 10/23/18 03:16 PM

Color is getting to be important to me on the big fish side to. More than just color may be a problem when color not right.
Posted by: Jim Wetzel

Re: Observation on Feed Fed Largemouth Bass - 10/23/18 03:28 PM

Check it out. We are doing another experiment in parallel that may be used to explore this further. Fish are of same cohort with fish on left fed a formulated diet while those on right are on forage dominated by invertebrates.


Posted by: jludwig

Re: Observation on Feed Fed Largemouth Bass - 10/23/18 03:40 PM

Can you share what you hope to learn from this experiment?
Posted by: Jim Wetzel

Re: Observation on Feed Fed Largemouth Bass - 10/23/18 03:59 PM

The experiment part is looking at ways to reduce cost of growing bass to 2 lbs. The methods in use currently producing changes that some pond managers not excited about when looks and other non-culinary considerations are involved.
Posted by: TGW1

Re: Observation on Feed Fed Largemouth Bass - 10/23/18 04:10 PM

Jim, are the pictured lmb the same age and are they in the same environment? And are the Northern's pictured on the left? In growing out Florida' in with high forage amounts of FHM's and BG along with RES and TFS, I saw some of the fish grow to 3 lbs from, 2" fingerlings in just 10 months here in Texas. Not all of them grew that fast but some of them did. Today, I am hand feeding some NLMB (not from fingerlings) with those same Florida and their growth has been outstanding, I think.
Posted by: Jim Wetzel

Re: Observation on Feed Fed Largemouth Bass - 10/23/18 04:16 PM

All same age in same pond.
Posted by: TGW1

Re: Observation on Feed Fed Largemouth Bass - 10/23/18 04:22 PM

From my exp. Spotted bass have most always been colored different and with more vibrant markings over Northerns. I assumed it was because I caught most of the spots near deeper water and in water with less color. But what I am seeing here, it may be due to what they eat?
Posted by: Bill D.

Re: Observation on Feed Fed Largemouth Bass - 10/23/18 05:17 PM

I wonder if it has anything to do with the fact that the fish on live forage need to be more aggressive to get a meal and display more color as a result. Those fish on commercial food have no need to be aggressive or expend energy to catch a pellet.
Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 10/23/18 05:39 PM

Jim,

You mentioned that the smaller fish were raised on invertebrates. They are big enough to be eating fish so what are you feeding them BSF, earthworms, crickets? If the formulated feed includes fish meal it might explain a lot of the difference in growth rates.
Posted by: scott69

Re: Observation on Feed Fed Largemouth Bass - 10/23/18 08:57 PM

my lmb are f1's (tiger bass from american sportfish). i have noticed right opposite as far as color goes. my lmb that take pellets have much more pronounced color contrast than the the ones that won't take pellets.

this is a very neat experiment you have going Jim. I hope you keep us updated.
Posted by: Shorty

Re: Observation on Feed Fed Largemouth Bass - 10/23/18 08:59 PM

Originally Posted By: Bill D.
I wonder if it has anything to do with the fact that the fish on live forage need to be more aggressive to get a meal and display more color as a result. Those fish on commercial food have no need to be aggressive or expend energy to catch a pellet.


It could also be that the fish on live forage are getting some micronutrients that the commercial food lacks. I had the same dull off colored look with a group of RES sunfish that I feed trained last year.
Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 10/24/18 01:30 AM

When he was sorting through the LMB from the electrofishing survey at my pond, Justin Stane made a similar observation. He could tell the difference between those that had hit the feed hard and those that had not just by their color differences.
Posted by: Dave Davidson1

Re: Observation on Feed Fed Largemouth Bass - 10/24/18 04:00 AM

Jim, are the pellet fed fish able to get any forage or only pellets? It would also be interesting if you could observe results over a life span. I wonder if the nutrient enriched quick growth could also mean a shorter life span.
Posted by: Jim Wetzel

Re: Observation on Feed Fed Largemouth Bass - 10/24/18 10:16 AM

Fish I am looking at directly are LMB's. Today we will see a similar pairing of spotted bass as well as more LMB's. Thus far with the LMB's all have access to forage and feed in a given pond. Some appear to specialize on pellets while other on forage. The second pond we saw much less size disparity between the two groups but color holds. Difference in color I think owing to micronutrient level (forms of vitamin A in this case). Other differences also noteworthy, but not being looked at directly at this time. Innards and jaws appear different. I can tell if a fish is on pellets or fish my feel alone, even when size not an issue. These differences might have implications on long-term survival.
Posted by: Bill Cody

Re: Observation on Feed Fed Largemouth Bass - 10/24/18 03:30 PM

Jim W - Excellent information and a great study. Glad you shared the info. Is it possible to provide a good picture of the "Innards" of both pellet fed and natural food fed bass? Try to make the amount of fat and liver color visible. Thanks again for doing this great practical application study.
Posted by: Jim Wetzel

Re: Observation on Feed Fed Largemouth Bass - 10/24/18 05:00 PM

This will tickle you.


Can you spot the fish feeding predominantly on feed? All from same pond.


Top are on feed. Note very large and pale livers plus lost of visceral fat. No digesta in GIT. Lower are on natural forage. Note darker and smaller liver with much less visceral fat. Stomach loaded with invertebrate prey.




My keyboard now smells like fish guts.
Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 10/24/18 06:16 PM

what type of feed was used?
Posted by: Centrarchid

Re: Observation on Feed Fed Largemouth Bass - 10/24/18 07:08 PM

Feed used is commercial formulated for Rainbow Trout. Most feeds will promote the problem.
Posted by: Bill Cody

Re: Observation on Feed Fed Largemouth Bass - 10/24/18 09:11 PM

JW Thanks for the great educational photos.
Posted by: Quarter Acre

Re: Observation on Feed Fed Largemouth Bass - 10/24/18 09:33 PM

If your keyboard smells bad...I can only imagine what you smell like. Thanks for the sacrifice! Very cool projects... Are you hiring?
Posted by: Centrarchid

Re: Observation on Feed Fed Largemouth Bass - 10/24/18 09:36 PM

Looking for motivated undergraduate research assistant.
Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 10/24/18 10:03 PM

Wish they had fishery studies when I was in college. smile
Posted by: Centrarchid

Re: Observation on Feed Fed Largemouth Bass - 10/24/18 10:12 PM

We do not do fisheries stuff here. Aquaculture with a little non-game fish biology.
Posted by: Acoursey

Re: Observation on Feed Fed Largemouth Bass - 10/25/18 08:02 AM

Carbohydrates are bad for LMB...

I am guessing that the digestible carbohydrate percentage in that feed is above 13%...
Posted by: Jim Wetzel

Re: Observation on Feed Fed Largemouth Bass - 10/25/18 09:22 AM

13% may also be too high, especially when taking into account cold winters where we are and further north. We just ran a trial with northern BG, 13% clearly causing a potential problem with that species.
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 10/25/18 12:26 PM

Agree with Jim. BG and LMB do not constructively use carbs much. Some pond fish do - like CC , Carp , some forage minnow type fish and oddly HSB which can get obese on carbs (not good to get obese). Also the closer the protein to the natural forage of a fish the better. The ideal protein concept is based on the premise that if the amino acid profile of the feed mimics the whole-body amino acid profile of the animal being fed, protein utilization and growth should be maximized.


Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 10/28/18 10:48 AM

Ahhh! So one group fends for itself on pond foods. But you said you are trying to find a cheaper way to grow LMB to two pounds. Will that comparison be made between trout feed and some other prepared feed?

I've always thought that it is not possible to improve on the quality of foods that mother nature provides from the nutrition standpoint. The fish not eating pellets must expend more energy for the food they get. Their food is concentrated with the nutrients they need and few (if any) of those they don't need. They are fitter and healthier even if they are smaller.
Posted by: Centrarchid

Re: Observation on Feed Fed Largemouth Bass - 10/28/18 11:19 AM

On the growout side no comparisons involving feed being made. Comparisons based on other factors during pond versus tank rearing. The problem appears with all commercial diets I have messed with to date. In the end I think formulated diets can match forages, just not there yet and not part of current objectives. Just getting a little insight as a byproduct of current work.
Posted by: Bill Cody

Re: Observation on Feed Fed Largemouth Bass - 10/28/18 08:20 PM

Centrarchid Jim - Have you explored or tried using the feeds in the Optimal Fish Food Family? One of their objectives is to formulate the healthiest foods for growing fish for the long term and trophy sizes. Bass diet is 44%/8%fat - nutrient rich low fat diet, designed to increase longevity
Posted by: Centrarchid

Re: Observation on Feed Fed Largemouth Bass - 10/28/18 08:41 PM

Currently trying to communicate with a supplier of one of their feed-stuffs. We know where science stands on nutritional requirements of LMB and BG's; we are trying push it ahead.
Posted by: optimalfishfood

Re: Observation on Feed Fed Largemouth Bass - 10/28/18 09:35 PM

Centrarchid,

This is a fantastic thread and a very active area of interest for us at Optimal. We are happy to answer questions or assist where we can. Please feel free to shoot me a call, text, or email!

-Dustin
Posted by: Jim Wetzel

Re: Observation on Feed Fed Largemouth Bass - 10/29/18 10:05 AM

Dustin,

We (includes Centrarchid) will be working with Bluegill where we are trying to use a more refined soybean product to get around some cost and health issues associated with current formulations. We just ran a Bluegill trial using more practical ingredients where we manipulated type and amounts of carbohydrate. Manuscript ready for submission on those findings. Bluegill, like LMB, have trouble managing carbohydrates. The grain side of formulations are likely causing the problem we currently see in our production ponds every year. We have resources in place to work with Bluegill over this winter indoors with small fish starting around 2". We are trying to drum up resources to do a larger parallel effort involving LMB where we treat 4" to 10" separately from fish being finished in the second year. It takes two growing seasons for us to hit 2 lbs and the second year has by far the highest feed cost. Research typically concentrates on smaller fish because easier / faster. We have resources to tackle fish approaching 2 lbs.

Jim
Posted by: snrub

Re: Observation on Feed Fed Largemouth Bass - 10/29/18 10:42 AM

I do not know what the relative cost or availability is of fish meal compared to plant based protein, but the amount of fish meal available on the market has to be a tiny portion of what plant based protein is available.

I can see where, through processing or other means, getting comparable results from a more plant based feed would be highly desirable from both an economic as well as possible sustainability standpoint.
Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 10/29/18 11:43 AM

Fish meal is essentially a by product fisheries and aquaculture. Clearly aquaculture cannot produce enough for itself so ocean bycatch and byproduct are important. Right now this byproduct is cheap but if these sources prove unsustainable the cost of feed for LMB and BG would be destined to rise considerably to reflect supply of this crucial ingredient.

Soybean meal has already been used successfully in the production of tilapia in China. So it has promise. But tilapia are herbivores to begin with and for this to have a major impact for carnivore feed will likely require genetic modification of soybeans, IMHO. This is a worthwhile effort, probably, as soybeans that are better for LMB will like be more nutritious for humans also.
Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 10/29/18 05:10 PM

I think animal/insect protein is far more practical substitute LMB/BG food base than plant protein. Even then, fishmeal is hard to replace due to importance of taurine, IIRC.
Posted by: optimalfishfood

Re: Observation on Feed Fed Largemouth Bass - 10/30/18 10:01 AM

Jim,

Very cool work. I'm excited to read your findings!!

We've done extensive work evaluating plant based proteins, especially soy. We've successfully grown salmonids on fish meal free diets on commercial scales using modified soy without common problems like enteritis or poor fcr.

Traditional feeds tend to view all ingredients on a protein basis and, to some extent, ignore the potentially bad components those ingredients bring with them. Starches are important to extrusion so they are difficult to eliminate completely...especially in a marketplace that likes floating feeds.

We work a lot with extrusion technology, feed formulations, and ingredient quality to design feeds around the nutrition and not the limitations of extrusion or least cost approaches.

I run a small extrutech extruder and make small test batches regularly. I'm happy to contribute what I can to aid in your research. This kind of work is very exciting and critical to improving feeds. Traditional feeds stem from markets where the goal is to grow fish quickly for human consumption...those are likely not the same diets that promote health and longevity. Shoot me an email and we can work out more details Dustin@optimalfishfood.com.

McDonalds is super cheap and sure helps increase my weight quickly...but I'm not sure its helps me in the long run.
Posted by: Matzilla

Re: Observation on Feed Fed Largemouth Bass - 10/30/18 11:13 AM

Originally Posted By: jpsdad
Fish meal is essentially a by product fisheries and aquaculture. Clearly aquaculture cannot produce enough for itself so ocean bycatch and byproduct are important. Right now this byproduct is cheap but if these sources prove unsustainable the cost of feed for LMB and BG would be destined to rise considerably to reflect supply of this crucial ingredient.

Soybean meal has already been used successfully in the production of tilapia in China. So it has promise. But tilapia are herbivores to begin with and for this to have a major impact for carnivore feed will likely require genetic modification of soybeans, IMHO. This is a worthwhile effort, probably, as soybeans that are better for LMB will like be more nutritious for humans also.


Asian carp from the Mississippi and Illinois rivers would be a great source for cheap(er) fishmeal. Someone should get with WIU to look into it http://www.wiu.edu/cas/biological_sciences/kibbe/index.php
Posted by: Jim Wetzel

Re: Observation on Feed Fed Largemouth Bass - 10/30/18 11:33 AM

Where I am at the Asian Carps are not going to be an economical activity for someone if the end use is as a fishmeal at going prices for the stuff. Fishing for them is hard on your expensive equipment and labor intensive. Commercial fishers already have a tough time making a buck where the end use if for direct human consumption. The fishmeal use of the same harvest would support even a smaller return for the fisherman. Using subsidies to support the harvesting and processing is not likely to be popular with tax payers unless they see worthwhile benefits related to reduction of carp abundance. Many people care, but not enough when cost are considered. Do you want to raise taxes to support the effort?
Posted by: 4CornersPuddle

Re: Observation on Feed Fed Largemouth Bass - 10/30/18 11:59 AM

I get what you're saying Jim.

I've wondered my whole life (I'm 68 now) about the problems created by common carp in many of our waters. I suppose commercial fishing and processing of these abundant, destructive pests has captured the attention of plenty of business-minded people over the years.

Properly designed capture methods could yield tonnage of carp for fish meal, for pet food, for fertilizer, etc. The question is what could these methods be!? I imagine nearly everything has been tried. Gill nets, electro-shocking, stupefying substances, traps, carp fishing derbies, on and on, come to mind. Refrigerated trucks or trailers stationed at collection points. Lots of other ideas.

And, I'd gladly pay a tax or an increase of my fishing license fee for effective carp reduction and the additional game fish populations that could result. In fact, I'd like to be able to earmark the license dollars I must contribute towards hatchery trout production to a cause of reducing carp. I'll take fewer hatchery "slimy" rainbows any day if it means fewer carp.
Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 10/30/18 12:09 PM

7.5 Billion humans and counting. The challenges of feeding a growing population continue to mount. Innovations like the one's Jim and anthropic mention will be necessary to maintain per capita fish consumption. The crimp on resources will be pervasive and we have to think ahead as Jim's work indicates we already are doing.
Posted by: Jim Wetzel

Re: Observation on Feed Fed Largemouth Bass - 10/30/18 12:24 PM

Originally Posted By: 4CornersPuddle
I get what you're saying Jim.

I've wondered my whole life (I'm 68 now) about the problems created by common carp in many of our waters. I suppose commercial fishing and processing of these abundant, destructive pests has captured the attention of plenty of business-minded people over the years.

Properly designed capture methods could yield tonnage of carp for fish meal, for pet food, for fertilizer, etc. The question is what could these methods be!? I imagine nearly everything has been tried. Gill nets, electro-shocking, stupefying substances, traps, carp fishing derbies, on and on, come to mind. Refrigerated trucks or trailers stationed at collection points. Lots of other ideas.

And, I'd gladly pay a tax or an increase of my fishing license fee for effective carp reduction and the additional game fish populations that could result. In fact, I'd like to be able to earmark the license dollars I must contribute towards hatchery trout production to a cause of reducing carp. I'll take fewer hatchery "slimy" rainbows any day if it means fewer carp.


Liberal, Tax and spend! Kidding.
Posted by: Jim Wetzel

Re: Observation on Feed Fed Largemouth Bass - 10/30/18 12:27 PM

Originally Posted By: jpsdad
7.5 Billion humans and counting. The challenges of feeding a growing population continue to mount. Innovations like the one's Jim and anthropic mention will be necessary to maintain per capita fish consumption. The crimp on resources will be pervasive and we have to think ahead as Jim's work indicates we already are doing.



We also need to eat lower on the aquatic food chain and eat smaller critters as well. Later I will try to show some crayfish and silverside / minnow options we have had fun here with among the students.
Posted by: Bob Lusk

Re: Observation on Feed Fed Largemouth Bass - 10/30/18 10:15 PM

We had a similar issue back in 2005 when we were getting serious about raising feed-trained bass in several recreational ponds, starting with Richmond Mill Lake in North Carolina. I called Dr. Mark Griffin, nutritionist with Purina Mills then, and we started to brainstorm. We'd been feeding a salmonid feed, and were worried about fatty livers and big fat deposits in guts of bass. Mark studied it and began to build a feed to match the nutrition for bass via pellets. Long story, but he did it by altering the amount of fish meal, changing the fat type and amount, adjusting the vitamins and micronutrients and pretty soon he'd invented AquaMax Largemouth, the best commercially produced feed for feed-trained bass. Fish fed that diet aren't blue, and don't have the big amounts of gut cavity stores of fat or fatty livers. When feeding the salmonid feed, we'd see Wr's of 150-170. After he adjusted the feed, I was really comfortable with 115-130 Wr's. Fish gain is excellent with much less accumulated fat. But, we still have to remember we are dealing with a predator fish designed to make a living off live fish.
Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 10/31/18 10:19 AM

Bob,

I've wondered if feed is lacking particularly in the nutrition required to grow fish in the dimension of length. Certainly, feed grows LMB and when preferred foods like fish are unavailable. Feed grows them much faster than a diet of crustaceans and insects as Jim's work shows.

I think it would be great to understand how the improvements in the feed formulation may have allowed or encouraged changes in feeding strategy. For example, were the feed rates in terms of pounds of feed continued at the prior rate? Or did the increased concentration of beneficial nutrients allow a reduced feed rate? Or perhaps did it alter the strategy by encouraging an increase in feed rate where fish grew longer faster albeit with less obesity.

From a feed supplier perspective, I wouldn't want to increase the cost of feed if I could if for no other reason to keep it affordable for those depending on it. We understand how the feed has improved the condition of fish, it would be useful to understand whether growth rates in weight and length were improved or to what extent these may have been sacrificed to produce healthier fish.
Posted by: Jim Wetzel

Re: Observation on Feed Fed Largemouth Bass - 10/31/18 10:48 AM

Originally Posted By: jpsdad
Bob,

I've wondered if feed is lacking particularly in the nutrition required to grow fish in the dimension of length. Certainly, feed grows LMB and when preferred foods like fish are unavailable. Feed grows them much faster than a diet of crustaceans and insects as Jim's work shows.

I think it would be great to understand how the improvements in the feed formulation may have allowed or encouraged changes in feeding strategy. For example, were the feed rates in terms of pounds of feed continued at the prior rate? Or did the increased concentration of beneficial nutrients allow a reduced feed rate? Or perhaps did it alter the strategy by encouraging an increase in feed rate where fish grew longer faster albeit with less obesity.

From a feed supplier perspective, I wouldn't want to increase the cost of feed if I could if for no other reason to keep it affordable for those depending on it. We understand how the feed has improved the condition of fish, it would be useful to understand whether growth rates in weight and length were improved or to what extent these may have been sacrificed to produce healthier fish.


My efforts discussed at top of thread did not test that well. I can grow LMB's at the genetic maximum using invertebrates alone, but the quantity and quality of such invertebrae forage required simply is not practical even in recreational pond settings. I can get growth in relatively large bass using just water fleas but the bass are not real good at sifting the critters requiring extremely high densities of prey. Bass can do things by changing behaviors you seldom if ever see then they have larger options like fish or even pellets that at first glance appear easier to consume.
Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 10/31/18 11:18 AM

Very interesting, particularly the part on water fleas.

Just be sure, I was implying that fish forage, in natural settings, if in sufficient supply, can grow LMB much faster than feed or invertebrate prey. Now this might be wrong as I've gleaned it from other's experience and studying other's research.

I would like to see more research on how hatchery feeding practices affect long term feeding behavior. I would think a 2lb bass is relatively dependent on feed if it were raised primarily on feed. It would be interesting to know how long it may take for one to make the transition to foraging BG.
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 10/31/18 12:15 PM

An interesting point on the length vs weight dynamics of LMB.


A number of years ago fisheries scientists studying trophy LMB and attempting to find a formula to accurately determine (estimate) weight based on length and girth made an interesting finding. There were after looking at thousands of trophy fish from diverse areas 2 distinct types of LMB (not talking about genetics here). The formulas devised used one calculation for short fish and another for long fish. All were very healthy and both formulas gave accurate weight results. Keep in mind that RW are just one measure and are based on a universal (set in time) average. I did not pursue this further at the time and never saw the specifics beyond the formulas.

As Jim noted LMB and other fish can adapt (plasticity) as that is in their genetics and that includes both feeding and nutrition. Some don't make it and others adapt and do. That is how a populations change over time.
Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 10/31/18 12:31 PM

Originally Posted By: ewest
An interesting point on the length vs weight dynamics of LMB.

As Jim noted LMB and other fish can adapt (plasticity) as that is in their genetics and that includes both feeding and nutrition. Some don't make it and others adapt and do. That is how a populations change over time.


From what you said here it would seem there may lie opportunity in a kind of "Share a Lunker" program for hatchery feed trained LMB. Fin clipped feed trained fish that achieve trophy size without additional feed might contribute greatly to the genetics of hatchery fish destined for recreational use.
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 10/31/18 01:19 PM

There is some research on the placing of feed trained LMB into existing populations of natural non-feed trained LMB. I have not looked at it in a while but the feed trained LMB did not do so well. There is other research that is not as conclusively negative. That is why if one is buying advanced LMB for stocking (6 inch or larger) that are feed trained it is better to get them that were placed into a growout pond at the hatchery including live forage. That is supplementally feed but not substantially reliant on feed.
Posted by: Matzilla

Re: Observation on Feed Fed Largemouth Bass - 10/31/18 02:14 PM

Originally Posted By: Jim Wetzel
Where I am at the Asian Carps are not going to be an economical activity for someone if the end use is as a fishmeal at going prices for the stuff. Fishing for them is hard on your expensive equipment and labor intensive. Commercial fishers already have a tough time making a buck where the end use if for direct human consumption. The fishmeal use of the same harvest would support even a smaller return for the fisherman. Using subsidies to support the harvesting and processing is not likely to be popular with tax payers unless they see worthwhile benefits related to reduction of carp abundance. Many people care, but not enough when cost are considered. Do you want to raise taxes to support the effort?


I don't think you would have to, Asian carp are already caught by commercial fishing nets up and down both rivers - the problem is there isn't a great demand for them, so they're often tossed back. If they were sold as a raw material for fish meal it would be a win win for all those involved. Some of the work WIU is doing focuses on tagging, tracking and telemetry to log the growth rates and migration patterns of Asian carp. When it comes to these fish invading Minnesota and the great lakes - several other agencies will get involved and those subsidies will come whether folks wish to pay or not. Look at zebra muscles...
Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 10/31/18 02:59 PM

Mat,

It's a too bad that there is no market for that bycatch. Also, it should be crime to put those fish back, I assume they are killing them first?
Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 10/31/18 03:24 PM

Carp are considered highly desirable in some Asian markets, including much of China. With modern freezing tech, why not send them there? Also, could be a cheap source of protein for prisons.

Would love to turn a nuisance fish into a resource, including fish meal.
Posted by: Jim Wetzel

Re: Observation on Feed Fed Largemouth Bass - 10/31/18 04:06 PM

Originally Posted By: anthropic
Carp are considered highly desirable in some Asian markets, including much of China. With modern freezing tech, why not send them there? Also, could be a cheap source of protein for prisons.

Would love to turn a nuisance fish into a resource, including fish meal.


That was tried somewhere in Kentucky, maybe a decade ago. Need to find out if they are still in operation. I personally do not want to export fish of a quality that would offend my buyers. The Missouri River here is not where I would want to get fish from if leg and digit number on kids to be kept normal.
Posted by: Quarter Acre

Re: Observation on Feed Fed Largemouth Bass - 10/31/18 04:17 PM

I recently heard the story about the Asian carp invasion, true or not - that's for you to decide, but, the story goes...it started near Jefferson City on a fish farm that was growing Asian Carp for table fare. The flooding of 1993 took the fish and allowed them to get into the Missouri River. They liked it, liked it ALOT.

I have had the opportunity to eat the Asian carp from the Missouri and it was very good. Now, I can not put it up there with salmon, but it certainly competes with LMB, panfish, and CC. In fact, I have had some pretty muddy catfish before and have yet to have any carp that should have been thrown back. The only downside is all the bones...one of these days I will pressure cook some and eat without the fear of choking.

EDIT: Aside from the cook's talent, the main thing to do is to cut the more yellow belly meat off and discard and some fish will have a blood vein that runs down the lateral line that should be removed as well.
Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 10/31/18 04:24 PM

Yeah, I've heard the same thing about carp. Quite edible if cooked right, though I personally have never tried. Grew up thinking of them as trash fish, but Asians and Europeans disagree. I suspect wild caught carp from the US would taste better than farm raised in China, considering all the stuff they put in the water there!

In England, a live 30 lb carp used to be worth thousands (not sure if still does). Not for eating, but for sport, rather like a 14 lb largemouth here.
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 10/31/18 04:41 PM

While not seen in the US in many countries process all kinds of fish for human consumption. The use of large amounts of fish (mostly from the sea) for conversion to fish meal for feeding fish is in some places met with the accusation that you are using the fish for recreation (U S production) while third world peoples are starving. Much like the argument that using corn for fuel results in starving people.

I am not starting a political discussion so please don't go there. Just pointing out that some take that position and it can/may effect our access to enough fish meal.
Posted by: Jim Wetzel

Re: Observation on Feed Fed Largemouth Bass - 10/31/18 04:42 PM

Originally Posted By: Quarter Acre
I recently heard the story about the Asian carp invasion, true or not - that's for you to decide, but, the story goes...it started near Jefferson City on a fish farm that was growing Asian Carp for table fare. The flooding of 1993 took the fish and allowed them to get into the Missouri River. They liked it, liked it ALOT.

I have had the opportunity to eat the Asian carp from the Missouri and it was very good. Now, I can not put it up there with salmon, but it certainly competes with LMB, panfish, and CC. In fact, I have had some pretty muddy catfish before and have yet to have any carp that should have been thrown back. The only downside is all the bones...one of these days I will pressure cook some and eat without the fear of choking.

EDIT: Aside from the cook's talent, the main thing to do is to cut the more yellow belly meat off and discard and some fish will have a blood vein that runs down the lateral line that should be removed as well.


Similar story I heard is that the source hatchery was in Arkansas. The original escapements occured back in the 1970's with low levels of natural reproduction occuring there after until the early 1990's when stars aligned and Bighead took off. Silver took of shortly their after. Ignoring Grass on this but they have been breeding since at least the 1980's where I have lived. The triploid rules on those came way too late. Black carp and Snakeheads will be in Missouri if not already present based on a stream biologist friend working for the MDC. They will be wild bred, not hatchery releases.
Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 10/31/18 05:34 PM

Originally Posted By: Jim Wetzel
Black carp and Snakeheads will be in Missouri if not already present based on a stream biologist friend working for the MDC. They will be wild bred, not hatchery releases.


That is an exceedingly unwelcome forecast. So are they (snakeheads) in the Mississippi river?
Posted by: Bill Cody

Re: Observation on Feed Fed Largemouth Bass - 10/31/18 08:48 PM

If the Asian carps get into the Great Lakes there will be job creation and some job security for the commercial fishermen (netters) who could harvest trash fish for the fish meal market.
Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 10/31/18 10:15 PM

Asian carps in the Great Lakes would be a catastrophe for the highly lucrative sports fisheries, which I strongly suspect would far outweigh any benefits from additional fishmeal.
Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 11/01/18 09:48 AM

Originally Posted By: ewest
While not seen in the US in many countries process all kinds of fish for human consumption. The use of large amounts of fish (mostly from the sea) for conversion to fish meal for feeding fish is in some places met with the accusation that you are using the fish for recreation (U S production) while third world peoples are starving. Much like the argument that using corn for fuel results in starving people.

I am not starting a political discussion so please don't go there. Just pointing out that some take that position and it can/may effect our access to enough fish meal.


In the end, I think its an economy and the fish meal must go to the highest bidder. There are strong incentives to find an alternative for aquaculture from the standpoint of availability and cost. I haven't seen any evidence that private sport fisheries consume enough of it to cause an impact like those described. So while such arguments are given room to air it is doubtful that they will have any significant influence.

It is possible that alternatives may have the impact of easing fishmeal demand and help to keep it more affordable in the future. We will have to see.
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 11/01/18 12:03 PM

I agree !
Posted by: snrub

Re: Observation on Feed Fed Largemouth Bass - 11/01/18 12:40 PM

Many, many years ago when I used to competition spearfish in SW Missouri we were allowed to spearfish only rough fish which include carp.

Wife and I cleaned and took some home one weekend and she pressure cooked it. It came out similar in taste and texture to canned tuna in my opinion. Maybe a little blander.

We made sandwitches like tuna fish sandwitches would be made with mayo and it was fine.

Certainly edible.
Posted by: Bill Cody

Re: Observation on Feed Fed Largemouth Bass - 11/02/18 11:12 AM

Asian carp in the Great Lakes is worse than a catastrophe. There are already way too many invasive exotic species in the Great Lakes and the USA.
Posted by: canyoncreek

Re: Observation on Feed Fed Largemouth Bass - 11/02/18 01:10 PM

Catastrophe? please elaborate? Are we talking about lost money or not enough food to go around or the ecosystem?

There is always drama about how much damage is done by raising animals for food, and soon we will have lab-made, cultured but real chicken meat made into chicken nuggets and other products. I'm sure all the poultry farmers would describe it as a catastrophe while the environmentally concerned folks would make it a national holiday.

Lets get real, if the Asian carp are already caught above all the barriers then they have to be in the Great Lakes already. Then the balance gets out of balance and soon it gets back in balance only differently than we planned on.
Posted by: Jim Wetzel

Re: Observation on Feed Fed Largemouth Bass - 11/02/18 02:07 PM

Catastrophe for native species, some at least, folks making money of the lucrative sport fishery and those making living off current assemblage of commercial species that will more likely than not be hammered.

Lakes are going to go through further changes anyway as they warm up. At some point LMB and BG are going to take off I think and that will be a problem as well even if the Asian carps do not make it in.
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 11/02/18 02:09 PM

Anytime an invasive species gets into an environment where it is an invader the potential for horrendous consequences exists. See cane toad or rabbits in Australia for example. I would say the Asian Carp is on the same scale.

Causing what is called a “trophic cascade”. For example, when American settlers wiped out wolves in Yellowstone National Park, this caused an increase in herbivores, which in turn led to a decrease in plants, which then caused a loss of birds.
Posted by: Jim Wetzel

Re: Observation on Feed Fed Largemouth Bass - 11/02/18 02:28 PM

Current state of the Great Lakes not exactly natural.
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 11/02/18 02:47 PM

No but it could get a lot worse if you get zebra mussels II (like a bad Halloween movie sequel) in the form of lots of A. carp.
Posted by: Jim Wetzel

Re: Observation on Feed Fed Largemouth Bass - 11/02/18 03:04 PM

The carps are going to get in at some point. Possibly an accident, loss of political will to fund, or eco-terrorism.
Posted by: snrub

Re: Observation on Feed Fed Largemouth Bass - 11/02/18 04:59 PM

About the only thing certain about the future is that things are going to change. Hopefully most of them for the better and not for the worse.
Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 11/02/18 05:31 PM

Well, life has gone through warm periods and cold periods before. Those species that can't adapt perish; those that can flourish.

One thing I wonder is if rising atmospheric CO2 levels impact pond plants (faster growth) similarly to land plants. Also, does CO2 fertilization result in greater productivity of periplankton & phytoplankton?
Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 11/02/18 05:43 PM

Well, life has gone through warm periods and cold periods before. Those species that can't adapt perish; those that can flourish.

I wonder if rising atmospheric CO2 levels impact pond plants (faster growth) similarly to land plants. Also, does CO2 fertilization result in greater productivity of periplankton & phytoplankton?
Posted by: Bill Cody

Re: Observation on Feed Fed Largemouth Bass - 11/02/18 08:08 PM

Back to LMB on pellets. How big as a documented size have any owners grown pellet raised LMB? Also has anyone verified how long LMB will live when feeding LMB primarily pellets or the LMB nuggets? We as a group should be documenting this information.
Posted by: Centrarchid

Re: Observation on Feed Fed Largemouth Bass - 11/02/18 08:39 PM

A female (Big Bertha) acquired as two pounder and feed trained after acquisition was pushing 10 lbs seven years later. She was put on forage every fall, overwintered in pond, and kept in large tank during summers after breeding for 4 of those years. Last three she was in a reservoir where she held court near an inlet that served as a feeding station. Most of her intake when given a choice was feed.

Last summer of life she suffered what looked like a broken back where weight was shed and she disappeared around time of fall turnover.

She was not pushed in terms of the amount of feed provided.

BG pushed do not do well long-term even though growth rapid and quality size easily reached. Death of those not always nutrition related; investment in repro chews them up.
Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 11/03/18 12:25 AM

Originally Posted By: Centrarchid
A female (Big Bertha) acquired as two pounder and feed trained after acquisition was pushing 10 lbs seven years later. She was put on forage every fall, overwintered in pond, and kept in large tank during summers after breeding for 4 of those years. Last three she was in a reservoir where she held court near an inlet that served as a feeding station. Most of her intake when given a choice was feed.

Last summer of life she suffered what looked like a broken back where weight was shed and she disappeared around time of fall turnover.

She was not pushed in terms of the amount of feed provided.

BG pushed do not do well long-term even though growth rapid and quality size easily reached. Death of those not always nutrition related; investment in repro chews them up.


What about Richmond Mill Lake? Seems they push BG pretty hard and have had enormous (literally & figuratively) success.
Posted by: Centrarchid

Re: Observation on Feed Fed Largemouth Bass - 11/03/18 07:17 AM

Originally Posted By: anthropic
Originally Posted By: Centrarchid
A female (Big Bertha) acquired as two pounder and feed trained after acquisition was pushing 10 lbs seven years later. She was put on forage every fall, overwintered in pond, and kept in large tank during summers after breeding for 4 of those years. Last three she was in a reservoir where she held court near an inlet that served as a feeding station. Most of her intake when given a choice was feed.

Last summer of life she suffered what looked like a broken back where weight was shed and she disappeared around time of fall turnover.

She was not pushed in terms of the amount of feed provided.

BG pushed do not do well long-term even though growth rapid and quality size easily reached. Death of those not always nutrition related; investment in repro chews them up.


What about Richmond Mill Lake? Seems they push BG pretty hard and have had enormous (literally & figuratively) success.



I implied nothing about a lack of success for me or anyone else. Concern I have is in respect to longevity of the fast growing fish as I keep them. They do not live as long as those reaching similar large size on natural forages.

We need to clarify points, otherwise this diversion from original discussion is folly.
Posted by: Bill Cody

Re: Observation on Feed Fed Largemouth Bass - 11/03/18 03:36 PM

Are there other forum members that have pictures or documentation for how big largemouth bass will get when fed primarily pellets?
Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 11/03/18 11:00 PM

Originally Posted By: Centrarchid
Originally Posted By: anthropic
Originally Posted By: Centrarchid
A female (Big Bertha) acquired as two pounder and feed trained after acquisition was pushing 10 lbs seven years later. She was put on forage every fall, overwintered in pond, and kept in large tank during summers after breeding for 4 of those years. Last three she was in a reservoir where she held court near an inlet that served as a feeding station. Most of her intake when given a choice was feed.

Last summer of life she suffered what looked like a broken back where weight was shed and she disappeared around time of fall turnover.

She was not pushed in terms of the amount of feed provided.

BG pushed do not do well long-term even though growth rapid and quality size easily reached. Death of those not always nutrition related; investment in repro chews them up.


What about Richmond Mill Lake? Seems they push BG pretty hard and have had enormous (literally & figuratively) success.



I implied nothing about a lack of success for me or anyone else. Concern I have is in respect to longevity of the fast growing fish as I keep them. They do not live as long as those reaching similar large size on natural forages.

We need to clarify points, otherwise this diversion from original discussion is folly.


Your observation about shortened lifespans of artificially fed BG is important, in my view. There's been quite a bit of discussion here about the topic, including what types of feed are most likely to cause issues such as fatty liver. And, of course, many folks here feed their fish, LMB and BG, including me.
Posted by: snrub

Re: Observation on Feed Fed Largemouth Bass - 11/03/18 11:37 PM

Another question would be, do fatty BG cause fatty LMB?

Fed BG makes fatty BG. Fed LMB makes fatty LMB. But do fatty fed BG eaten by LMB that are not fed cause fatty LMB?

In other words, does feeding the BG pass on bad things up the food chain?
Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 11/04/18 12:44 AM

John, with humans it's been pretty well demonstrated that, contrary to "expert" government advice, eating natural fat does not make you fat. Sugar, processed fats such as corn oil, and simple carbs are the culprits.

If this holds with fish, perhaps fat prey fish don't make predators fat. It would be interesting research!
Posted by: Centrarchid

Re: Observation on Feed Fed Largemouth Bass - 11/04/18 06:30 AM

Originally Posted By: anthropic
John, with humans it's been pretty well demonstrated that, contrary to "expert" government advice, eating natural fat does not make you fat. Sugar, processed fats such as corn oil, and simple carbs are the culprits.

If this holds with fish, perhaps fat prey fish don't make predators fat. It would be interesting research!


Where does the government say eating natural food makes you fat? I am not aware such and need to be if it exists.
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 11/05/18 10:34 AM

Originally Posted By: snrub
Another question would be, do fatty BG cause fatty LMB?

Fed BG makes fatty BG. Fed LMB makes fatty LMB. But do fatty fed BG eaten by LMB that are not fed cause fatty LMB?

In other words, does feeding the BG pass on bad things up the food chain?


Good question and I don't know the answer. I do have a WAG. I guess that the LMB eating fed BG will convert the BG to what a LMB needs and that the source of the BG fat will be irrelevant. I could easily be wrong on this.

Based on my reading natural sources of food lead to a healthier fish population. When combined with supplemental feeding (low % of total nutrition) you get the best of both . I have not seen any info indicating that for long term health purposes that completely feed dependent fish is the better course.
Posted by: snrub

Re: Observation on Feed Fed Largemouth Bass - 11/05/18 10:45 AM

That would be my best guess also Eric.

I just brouht it up because it seemed to be the next logical question in the nutrient equasion discussion.
Posted by: snrub

Re: Observation on Feed Fed Largemouth Bass - 11/05/18 10:52 AM

Another bottom line question that I entertained is "Does a person want a 12# 7 year old bass, or a 7# 12 year old bass?" .

And the answer could be different for different people with different goals.

For a trophy hunter, the shortened life might be worth it. For a public lake manager, having a diverse "good fishing" population (with longer life) might be a more realistic goal.
Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 11/05/18 11:33 AM

Originally Posted By: ewest
Originally Posted By: snrub
Another question would be, do fatty BG cause fatty LMB?

Fed BG makes fatty BG. Fed LMB makes fatty LMB. But do fatty fed BG eaten by LMB that are not fed cause fatty LMB?

In other words, does feeding the BG pass on bad things up the food chain?


Good question and I don't know the answer. I do have a WAG. I guess that the LMB eating fed BG will convert the BG to what a LMB needs and that the source of the BG fat will be irrelevant. I could easily be wrong on this.

Based on my reading natural sources of food lead to a healthier fish population. When combined with supplemental feeding (low % of total nutrition) you get the best of both . I have not seen any info indicating that for long term health purposes that completely feed dependent fish is the better course.


It is well known that differing foods fed cladocerans result in forage of differing quality for raising fish fry. The quality of tilapia as food for humans declines the more dependent the fish were on a prepared diet where the most healthy fish in terms of omega 3's were raised on green water.

To be sure, grain feeding forage doesn't produce a diet as healthy for LMB as those raised on natural forages. Even so, the extent it may adversely affect the health of LMB would be rather muted in the light of the feeding rates that most people feed at. In other words, the forage doesn't depend to a great extent on feed.

I do think however that LMB that are feed trained are much more dependent on feed than BG which need no training.

Originally Posted By: ewest


When combined with supplemental feeding (low % of total nutrition) you get the best of both .


I am sorry but this hardly makes sense to me smile
Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 11/05/18 11:36 AM

Originally Posted By: snrub
Another bottom line question that I entertained is "Does a person want a 12# 7 year old bass, or a 7# 12 year old bass?" .



There are a lot of folks who would gladly settle for either!
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 11/05/18 09:31 PM

Originally Posted By: jpsdad
.

Originally Posted By: ewest


When combined with supplemental feeding (low % of total nutrition) you get the best of both .


I am sorry but this hardly makes sense to me smile


The biggest inhibitor to good fish growth and health is insufficient food. This comes up over and over and over in studies. IMO the best conditioned fish are those with a mostly natural diet but with a small (low %)amount of supplemental feeding to insure enough nutrition. Hope this helps.
Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 11/06/18 02:17 AM

Originally Posted By: Centrarchid
Originally Posted By: anthropic
John, with humans it's been pretty well demonstrated that, contrary to "expert" government advice, eating natural fat does not make you fat. Sugar, processed fats such as corn oil, and simple carbs are the culprits.

If this holds with fish, perhaps fat prey fish don't make predators fat. It would be interesting research!


Where does the government say eating natural food makes you fat? I am not aware such and need to be if it exists.


Unfortunately for public health, in the 1960s/70s the US government decided that dietary fats caused obesity and heart disease. Their recommendation was to eat lots of grains (pasta, bread, etc) and minimize fatty food such as butter, whole milk, beef, etc. Skim milk, margarine instead of butter were supposedly better alternatives.

We now know that a diet high in natural fats does not increase obesity & heart disease. Olive oil, lard, salmon, milk fat: consumption usually correlates with lower mortality, not higher.

I don't eat "low fat" foods because typically the missing flavorful fat is replaced by flavorful sugars, often corn syrup. Sugars spike insulin, which often leads to diabetes & obesity. Simple carbs like flour do the same.
Posted by: Centrarchid

Re: Observation on Feed Fed Largemouth Bass - 11/06/18 04:34 AM

For crying out loud, that is not recent. Therefore not accurate portrait of what the recommendations are.
Posted by: NEDOC

Re: Observation on Feed Fed Largemouth Bass - 11/06/18 08:01 AM

I think it's an accurate description of what many still believe, largely because of the dietary recommendations from the 60s thru the 90s. You wouldn't believe how many people think I'm crazy when I recommend diets high in fats and low in carbs.
Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 11/06/18 09:42 AM

I was nodding my head at everything ... until you closed with this.

Originally Posted By: ewest

. . . but with a small (low %)amount of supplemental feeding to insure enough nutrition.


This would seem to imply that fish can't get enough nutrition without supplemental feeding.. . a notion I would certainly disagree with and that is completely unsupported by science. For one thing one can certainly imagine scenarios where the amount of supplemental feeding you might recommend is insufficient to ensure enough nutrition. Under such a scenario, we can all agree that it isn't the feed's fault. There's just too many fish.

If this is true when artificial feeds are insufficient then it is equally true when natural foods are insufficient.

It has been long known that the ultimate size of fish is independent of fertility. A pond which supports 150 lbs/acre standing weights can produce fish of equal size to a pond that supports 500 lbs/acre standing weight. I know you know this Eric but based on some things I've seen written here, some certainly don't.

One should feed to have more fish ... not bigger fish. If one wants bigger fish the results of feeding will only meet that goal in the short term.

Posted by: TGW1

Re: Observation on Feed Fed Largemouth Bass - 11/06/18 09:55 AM

In response to Jim's question or statement where the feed trained had faster growth but lacked the color or that lateral line being more visible. At my pond, I added feed trained lmb last June and since then they have been hand feed Aquamax LMB 5 to 6 days per week. I saw my feed trained are colored or lack of color as seen in his photo where he compared the lmb coloring. So, I have been cutting back on the feed due to me not being available everyday to feed them. Question is, will these 2 to 3 lb, 15" to 17" lmb revert back to a more natural look when feed is cut back and will the lmb adapt to eating Bg, Res, Tp and Tfs? And with lots of available natural forage, will I continue to see good growth with the lmb if the feed is cut back? Have they adjusted to eating more forage? They have been in the pond for 6 months and I was hoping they have adjusted to their new environment by now and have learned how to eat natural forage.
Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 11/06/18 10:11 AM

Eric mentions research, some positive ... others more negative, on the ability of feed trained LMB to transition to a life without feed. Often research is not available without paying access to it. If not copyright protected or if available from free sources, perhaps Eric can point us to online sources of this research.

Bump ...

I think the timing of cutting the feed couldn't be better. The TP will be easier for your FT LMB to catch over then next 10 weeks as they start the process of dying. Also through winter the LMB will be a little more active than BG.
Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 11/06/18 10:19 AM

The gold standard, I think, is feed trained LMB which have also learned to eat their natural prey. My understanding is that some fishmongers have trained their LMB that way before selling.
Posted by: TGW1

Re: Observation on Feed Fed Largemouth Bass - 11/07/18 07:23 AM

These FT lmb have an outstanding RW most likely from feeding the Aquamax so I guess I will monitor and see what happens as I reduce the amount of feed. Either that or get them to feed at a different time of day, so I might be able to continue the daily feeding. Right now if I feed at a different time from what they are used to, I get little or no fish feeding.
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 11/08/18 04:18 PM

With temps falling LMB should not eat as much.
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 11/08/18 04:23 PM

Here is some info. I will find some more.


Pellet-reared Largemouth Bass Competitive Ability at Various Levels of Exposure to Live Forage
Kyle T. Rachels, Aquaculture/Fisheries Center, University of Arkansas at Pine Bluff, 1200 N. University, Mail Slot 4912, Pine Bluff, AR 71601
Gordon R. Taylor, Aquaculture/Fisheries Center, University of Arkansas at Pine Bluff, 1200 N. University, Mail Slot 4912, Pine Bluff,
AR 71601
Brandon M. Baumhoer, Aquaculture/Fisheries Center, University of Arkansas at Pine Bluff, 1200 N. University, Mail Slot 4912, Pine Bluff,
AR 71601
Sagar Shrestha, Aquaculture/Fisheries Center, University of Arkansas at Pine Bluff, 1200 N. University, Mail Slot 4912, Pine Bluff, AR 71601
Steve E. Lochmann, Aquaculture/Fisheries Center, University of Arkansas at Pine Bluff, 1200 N. University, Mail Slot 4912, Pine Bluff,
AR 71601
Abstract: We investigated the effects of exposing pellet-reared, advanced-fingerling largemouth bass (Micropterus salmoides) to live forage on the ability
of bass to capture live forage (competitive ability). Wild and pellet-reared largemouth bass were paired in competitive trials in 75-L aquaria and offered
live fathead minnows (Pimephales promelas). Prior to competitive trials, pellet-reared largemouth bass were placed into trial groups and fed fathead
minnows daily for 0, 2, 4, 8, and 16 days among groups. Pellet-reared largemouth bass without exposure to live forage captured the fathead minnow in
9% of competitive events against wild fish and captured significantly fewer fathead minnows than pellet-reared largemouth bass with exposure to live
forage (logistic regression; P < 0.05). Pellet-reared largemouth bass with exposure to live forage before competitions were similar to wild largemouth
bass in competitive ability. Regression analysis predicted pellet-reared largemouth bass with nine days of prestocking live forage exposure would have a
similar ability to compete for food as wild largemouth bass. Providing pellet-reared largemouth bass with live forage for nine days before stocking may
provide the benefits of both pellet and live-forage rearing.

Our data revealed substantial differences in competitive ability
between wild and hatchery largemouth bass reared exclusively on
pellets. Wild fish captured the minnow in 10 of the 11 pairwise
comparisons. These results illuminate a mechanism that potentially
contributes to the high mortality observed in stocking programs
conducted with pellet-reared largemouth bass (e.g., Heidinger and
Brooks 2002, Porak et al. 2002, Janney 2006, Thomas and Dockendorf
2009). Even if pellet-reared fish are able to learn to identify
natural food items post-stocking, they may continue to be outcompeted
by wild fish. Individuals that lose a competition have a
lower probability of winning future competitions than individuals
that have established dominance or individuals without previous
competition experience (Beacham and Newman 1987). Tiira et al.
(2009) found individuals that lost initial competitions grew less
over 8 mo than the individuals that won competitions. They also
found relative dominance was stable over long periods, with initial
competition winners maintaining dominance over losers after 8
mo. If food is limiting and pellet-reared largemouth bass are poor
competitors, as demonstrated in this study, they might contribute
little to the population in which they are stocked.
Posted by: TGW1

Re: Observation on Feed Fed Largemouth Bass - 11/08/18 04:53 PM

Eric, Thanks for all the information you provide here. So, I got to thinking about it all since I am new to having feed trained lmb in the pond. First off these lmb were provided by Todd Overton from his fish located in Northern Okla. I think they came from a pond of his there. He sold them as a two and a half pond lmb and for the most part they were that size with some of them being a bit larger. We did fin clip them and took out the ones I thought were males based on their size and shape (skinnier and smaller). All in all, I was well pleased with them when he delivered them to the pond. And so I have been sampling some of them through fishing, using plastics along with some double willow leaf spinner baits. I'm a little mentally slow sometimes (DUH !) but since I have caught them on spinners they must be feeding on forage fish or a spinner bait would not attract them. Or at least that is my thinking now. And I have seen some really good RW's and watch these fish when they are hand feed. Last week my water temps were 73 at the surface and 70 at 4 foot deep. I am sure that temp has dropped some in the last couple of days with cooler days along with some rain. I plan to continue to feed them but I may need to get them to change their feeding times some. Or locate and spend the money for a feeder that will throw the Aquamx lmb feed.
Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 11/09/18 07:45 AM

Good info!
Posted by: bassmaster61

Re: Observation on Feed Fed Largemouth Bass - 11/09/18 10:08 AM

I will say that our feed trained LMB have taken our lures to some extent this last season. They were stocked into our pond as 1-1.25 lb. fish in early June 2017. We have intentionally tried to not fish around the feeder area (we will starting next season) but this is in a small 1.6 acre BOW so I would assume the fish do get around to other parts of the pond as well.

We had no trouble meeting our maintenance harvest target of 32 LMB under 14" in length during the 2018 season. At the time they were stocked, all fish were 14" or slightly larger so we know that none of the stocker LMB were harvested. Many of the fish hanging around the feeder appear to be in excess of 3 lbs. We caught probably 4 fish in the 3+ lb. size range from the pond this year. Originally 55 were stocked into the existing LMB population in this 70 year old pond. Prior to stocking, this pond's LMB population was stunted so we harvested 60 fish or approximately 40 per surface acre.

I have only been feeding a total of 2 lbs. of pellets each day (1 lb. twice each day) hoping these stockers would also learn to eat natural forage. We also stocked in 400 adult native northern feed trained BG (5"-7") at the same time as the LMB.

Eric's info is kind of a bummer since the studies show that stockers are not very good at getting on natural forage. We will see what happens in our pond. Feeding fish is an experiment for us and if we start catching a decent number of large stockers on standard tackle next year I will consider it a success. But just in case, I am tying a few flies that look like Aquamax MVP pellets.....BM61.

Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 11/09/18 05:02 PM

Well, if you aren't feeding very heavily and the LMB are gaining weight rapidly, they must be eating some natural forage.
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 11/12/18 01:15 PM

Originally Posted By: jpsdad
I was nodding my head at everything ... until you closed with this.

Originally Posted By: ewest

. . . but with a small (low %)amount of supplemental feeding to insure enough nutrition.


This would seem to imply that fish can't get enough nutrition without supplemental feeding.. . a notion I would certainly disagree with and that is completely unsupported by science. For one thing one can certainly imagine scenarios where the amount of supplemental feeding you might recommend is insufficient to ensure enough nutrition. Under such a scenario, we can all agree that it isn't the feed's fault. There's just too many fish.

If this is true when artificial feeds are insufficient then it is equally true when natural foods are insufficient.

It has been long known that the ultimate size of fish is independent of fertility. A pond which supports 150 lbs/acre standing weights can produce fish of equal size to a pond that supports 500 lbs/acre standing weight. I know you know this Eric but based on some things I've seen written here, some certainly don't.

One should feed to have more fish ... not bigger fish. If one wants bigger fish the results of feeding will only meet that goal in the short term.



Not disagreeing just adding clarity. The biggest problem encountered by most ponds (not all)is lack of adequate nutrition. The reasons vary from to many fish , out of balance populations ,poor harvest management, natural disasters (weather related mostly), poor productivity (not fertile), water quality issues and others. That is a generality for our readers and not an assertion of any particular managed pond.

Yes there are waters that need nothing and can support over a thousand lbs of fish per acre. There are also a lot that can only support 50 lbs per acre with out help. The biggest problem is skinny fish and the easiest way to efficiently fix that is more food and harvest. Total population mgt is not about if you can grow a few big fish as that is common in non-managed low nutrient ponds as well. In most BG/LMB ponds supp. feeding of BG is very efficient and mostly results in better conditioned populations when used in connection with proper harvest.
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 11/12/18 01:26 PM

More info as requested.


North American Journal of Fisheries Management 38:794–802, 2018
© 2018 American Fisheries Society


Effect of Rearing Experience on the Survival, Growth, and Behavior of
Hatchery-Reared Largemouth Bass
Matthew J. Diana,*1 Brett J. Diffin,2 Lisa M. Einfalt, and David H. Wahl

Abstract
Largemouth Bass Micropterus salmoides are commonly stocked throughout their native range, but survival of
stocked fish is variable and often low. Hatchery fish may have difficulty switching to natural forage; therefore, providing
feeding experience with natural prey in the rearing environment could result in improved growth and survival of
Largemouth Bass after stocking. We conducted pond experiments to evaluate differences in growth and survival of
Largemouth Bass reared in raceways and fed pellets or in ponds and fed either Bluegill Lepomis macrochirus prey or
Fathead Minnow Pimephales promelas prey. Largemouth Bass reared on one of these three diets were stocked into
ponds containing Bluegill prey. After 2 months, pellet-reared Largemouth Bass were significantly smaller than fish
reared either on Fathead Minnows or Bluegills, whereas fish reared on either Fathead Minnows or Bluegills were similar.
Fathead Minnow-reared Largemouth Bass had lower survival than Bluegill-reared fish, but no other survival differences
were observed. To determine possible mechanisms influencing differential growth and survival of juvenile
Largemouth Bass, we also conducted laboratory experiments examining the influence of prior feeding experience (pellets,
Bluegills, or Red Shiners Cyprinella lutrensis) on foraging behavior and prey capture success in pools. Largemouth
Bass reared on live forage captured prey faster, ingested more prey, and had higher capture efficiencies than
did fish reared on pellets. Combined, pond and laboratory experiments show prior acclimation to live prey may ultimately
be beneficial to increasing growth of stocked hatchery Largemouth Bass and could result in increased recruitment.
We recommend additional exploration of acclimation of Largemouth Bass fingerlings to natural prey,
preferably Bluegills, prior to stocking to determine whether hatchery managers should consider alternative rearing
techniques.

Rearing Largemouth Bass Micropterus salmoides for
supplemental stocking is a common practice throughout
their range. Hatchery rearing techniques vary, but fish are
most often raised on a pellet diet in artificial systems.
Although this method is efficient at producing large quantities
of fish, poststocking survival rates can be low or
variable (Boxrucker 1986; Porak et al. 2002; Hoffman and
Bettoli 2005; Diana and Wahl 2008, 2009). Less-common
rearing techniques for Largemouth Bass include rearing in
ponds with minnow prey or introducing natural prey into
the hatchery diet. In these conditions, hatchery fish gain
experience foraging on live prey or acclimate to a more
natural environment before being stocked, and these methods
can be beneficial to poststocking growth or survival
for other species (Szendrey and Wahl 1995; Larscheid
et al. 1999; Czerniawski et al. 2015). Using more natural
pond environments and prey for rearing Largemouth Bass
may increase growth and survival after stocking.

Largemouth Bass that had prior experience preying on
natural prey exhibited advantages in growth and feeding
success than did pellet-reared fish. While all treatments
showed equal recognition of prey by initiating follow
behavior and engaging similarly in precapture behaviors
(follows, strikes, time moving), prior experience with live
prey improved capture success. Largemouth Bass reared
on live prey captured prey faster, captured more prey, and
had higher capture efficiencies than did pellet-reared bass.
When exposed to natural prey, fish become more effective
at capturing prey, as observed for tiger muskellunge
(Muskellunge Esox masquinongy × Northern Pike E.
lucius) (Gillen et al. 1981), Walleye (Wahl et al. 1995),
Chinook Salmon Oncorhynchus tshawytscha (Maynard
et al. 1996), Brown Trout (Sundstrom and Johnsson
2001), and Spotted Seatrout Cynoscion nebulosus (Jackson
et al. 2013). Pellet-reared Largemouth Bass had difficulty
capturing either prey type within a laboratory pool, and
we would expect these results to be magnified in a field
setting, where prey are not confined and can escape. Since
Largemouth Bass acclimated to live prey performed similarly
in pond and laboratory experiments, feeding experience
with any live prey may be more important for
Largemouth Bass than is prey type. However, we did
observe evidence of increased feeding success for Bluegillreared
Largemouth Bass in extended feeding trials (2 h) as
they captured more Bluegills than Red Shiners compared
with minnow-reared fish.
Even small differences in feeding efficiency can result in
growth differences that may have implications for survival.
Size of age-0 Largemouth Bass in the fall has been
related to overwinter survival with smaller fish experiencing
greater mortality (Miranda and Hubbard 1994; Ludsin
and Devries 1997; Garvey et al. 1998; Post et al. 1998).
Stocked Largemouth Bass overwinter survival is also size
dependent, and larger-sized individuals in the fall have
better survival (Diana and Wahl 2008). Throughout the
growing season, larger-sized juvenile piscivores can maintain
a competitive advantage over smaller cohorts (Ludsin
and Devries 1997). Larger individuals have a wider gape
resulting in better prey capture and lower handling times
(Einfalt et al. 2015; Detmer et al. 2018) and can also feed
on a larger proportion of the prey population resulting in
a greater availability of fish prey (Hambright et al. 1991).
In this study, the weight of pellet-reared Largemouth Bass
was only 80% of the weight of fish that had prior exposure
to fish prey. The smaller size of the pellet-reared fish could
result in differential recruitment due to higher overwinter
mortality.


Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 11/12/18 01:36 PM

While it may be true that a pond with 150 lb of LMB can grow equally very large fish as a pond with 500 lb of LMB, wouldn't the latter grow about three times as many?
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 11/12/18 01:39 PM

All other things being equal - yes. Its getting and keeping all other things equal that is the challenge. A big issue is being able to catch those big fish.
Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 11/12/18 01:40 PM

Originally Posted By: ewest
More info as requested.


North American Journal of Fisheries Management 38:794–802, 2018
© 2018 American Fisheries Society


Effect of Rearing Experience on the Survival, Growth, and Behavior of
Hatchery-Reared Largemouth Bass
Matthew J. Diana,*1 Brett J. Diffin,2 Lisa M. Einfalt, and David H. Wahl

Abstract
Largemouth Bass Micropterus salmoides are commonly stocked throughout their native range, but survival of
stocked fish is variable and often low. Hatchery fish may have difficulty switching to natural forage; therefore, providing
feeding experience with natural prey in the rearing environment could result in improved growth and survival of
Largemouth Bass after stocking. We conducted pond experiments to evaluate differences in growth and survival of
Largemouth Bass reared in raceways and fed pellets or in ponds and fed either Bluegill Lepomis macrochirus prey or
Fathead Minnow Pimephales promelas prey. Largemouth Bass reared on one of these three diets were stocked into
ponds containing Bluegill prey. After 2 months, pellet-reared Largemouth Bass were significantly smaller than fish
reared either on Fathead Minnows or Bluegills, whereas fish reared on either Fathead Minnows or Bluegills were similar.
Fathead Minnow-reared Largemouth Bass had lower survival than Bluegill-reared fish, but no other survival differences
were observed. To determine possible mechanisms influencing differential growth and survival of juvenile
Largemouth Bass, we also conducted laboratory experiments examining the influence of prior feeding experience (pellets,
Bluegills, or Red Shiners Cyprinella lutrensis) on foraging behavior and prey capture success in pools. Largemouth
Bass reared on live forage captured prey faster, ingested more prey, and had higher capture efficiencies than
did fish reared on pellets. Combined, pond and laboratory experiments show prior acclimation to live prey may ultimately
be beneficial to increasing growth of stocked hatchery Largemouth Bass and could result in increased recruitment.
We recommend additional exploration of acclimation of Largemouth Bass fingerlings to natural prey,
preferably Bluegills, prior to stocking to determine whether hatchery managers should consider alternative rearing
techniques.

Rearing Largemouth Bass Micropterus salmoides for
supplemental stocking is a common practice throughout
their range. Hatchery rearing techniques vary, but fish are
most often raised on a pellet diet in artificial systems.
Although this method is efficient at producing large quantities
of fish, poststocking survival rates can be low or
variable (Boxrucker 1986; Porak et al. 2002; Hoffman and
Bettoli 2005; Diana and Wahl 2008, 2009). Less-common
rearing techniques for Largemouth Bass include rearing in
ponds with minnow prey or introducing natural prey into
the hatchery diet. In these conditions, hatchery fish gain
experience foraging on live prey or acclimate to a more
natural environment before being stocked, and these methods
can be beneficial to poststocking growth or survival
for other species (Szendrey and Wahl 1995; Larscheid
et al. 1999; Czerniawski et al. 2015). Using more natural
pond environments and prey for rearing Largemouth Bass
may increase growth and survival after stocking.

Largemouth Bass that had prior experience preying on
natural prey exhibited advantages in growth and feeding
success than did pellet-reared fish. While all treatments
showed equal recognition of prey by initiating follow
behavior and engaging similarly in precapture behaviors
(follows, strikes, time moving), prior experience with live
prey improved capture success. Largemouth Bass reared
on live prey captured prey faster, captured more prey, and
had higher capture efficiencies than did pellet-reared bass.
When exposed to natural prey, fish become more effective
at capturing prey, as observed for tiger muskellunge
(Muskellunge Esox masquinongy × Northern Pike E.
lucius) (Gillen et al. 1981), Walleye (Wahl et al. 1995),
Chinook Salmon Oncorhynchus tshawytscha (Maynard
et al. 1996), Brown Trout (Sundstrom and Johnsson
2001), and Spotted Seatrout Cynoscion nebulosus (Jackson
et al. 2013). Pellet-reared Largemouth Bass had difficulty
capturing either prey type within a laboratory pool, and
we would expect these results to be magnified in a field
setting, where prey are not confined and can escape. Since
Largemouth Bass acclimated to live prey performed similarly
in pond and laboratory experiments, feeding experience
with any live prey may be more important for
Largemouth Bass than is prey type. However, we did
observe evidence of increased feeding success for Bluegillreared
Largemouth Bass in extended feeding trials (2 h) as
they captured more Bluegills than Red Shiners compared
with minnow-reared fish.
Even small differences in feeding efficiency can result in
growth differences that may have implications for survival.
Size of age-0 Largemouth Bass in the fall has been
related to overwinter survival with smaller fish experiencing
greater mortality (Miranda and Hubbard 1994; Ludsin
and Devries 1997; Garvey et al. 1998; Post et al. 1998).
Stocked Largemouth Bass overwinter survival is also size
dependent, and larger-sized individuals in the fall have
better survival (Diana and Wahl 2008). Throughout the
growing season, larger-sized juvenile piscivores can maintain
a competitive advantage over smaller cohorts (Ludsin
and Devries 1997). Larger individuals have a wider gape
resulting in better prey capture and lower handling times
(Einfalt et al. 2015; Detmer et al. 2018) and can also feed
on a larger proportion of the prey population resulting in
a greater availability of fish prey (Hambright et al. 1991).
In this study, the weight of pellet-reared Largemouth Bass
was only 80% of the weight of fish that had prior exposure
to fish prey. The smaller size of the pellet-reared fish could
result in differential recruitment due to higher overwinter
mortality.




Do fish hatcheries acclimate their LMB to natural forage prior to stocking? How can we find out?
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 11/12/18 01:44 PM

Some do - you have to ask and or insist. If it is your initial stocking of LMB and you have a forage base and will be feeding it should not be an issue. We were discussing stocking feed trained LMB into an existing pond with LMB.
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 11/12/18 02:02 PM

More info

North American Journal of Fisheries Management 38:1039–1049, 2018
© 2018 American Fisheries Society

Poststocking Survival of Conditioned and Pond-Reared Compared to
Indoor Pellet-Reared Advanced Fingerling Florida Bass
Nicholas A. Trippel* and Wesley F. Porak
Erin H. Leone

Abstract
Supplemental stocking of hatchery Largemouth Bass Micropterus salmoides and Florida Largemouth Bass Micropterus
salmoides floridanus (hereafter, Florida Bass) is a common practice around the world, but the results commonly
do not meet expectations. Predation upon stocked fish and the inefficiency of stocked fish in capturing wild prey are
common reasons for low poststocking survival rates of hatchery fish. Standard protocol for rearing Florida Bass in
Florida includes growing fish out in indoor raceways with pellet feed until 5 d prior to stocking, when live prey is introduced.
We conducted a 3-year study to determine whether extended conditioning in outdoor ponds, exposure to predators
prior to stocking, or rearing in ponds rather than indoor raceways could increase the survival of hatchery-reared
Florida Bass. One month after stocking, mean survival for standard hatchery-reared fish that received pellets was 36%
(SE = 4.3) across all 3 years. Mean survival was 63% (SE = 4.7) for experimental fish conditioned with predators (ECWP),
41% (SE = 4.8) for fish conditioned without predators (E-CWOP), and 63% (SE = 5.4) for fish raised on live
prey in outdoor ponds in the absence of predators (E-PR). While stocked in research ponds, E-CWP and E-PR fish
had higher growth rates than standard pellet-reared fish. During laboratory trials to measure predator avoidance rates,
which began 24 h after experimental ponds were stocked, standard pellet-reared fish had a mean 48-h survival rate of
84% (SE = 6.6). Mean 48-h survival for the E-CWP, E-CWOP, and E-PR groups was 96% (SE = 1.9), 84%
(SE = 7.2), and 95% (SE = 3.1), respectively. Our experiments indicate that being reared outside or conditioning to a
natural environment and exposure to predators may increase poststocking survival of hatchery-reared Florida Bass.
Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 11/12/18 02:30 PM

Yeah, that is my situation, adding feed trained LMB to a BOW that already has them. Worked real well with N LMB stocked last fall, thinking about doing it with F1 next fall.
Posted by: TGW1

Re: Observation on Feed Fed Largemouth Bass - 11/14/18 08:32 AM

Lets take Jim's experiment a little farther, if we can. We have lmb that are feed trained with a diet of fish food (pellets). He is showing some nice growth with these lmb. I understand it is in a lab environment. So, if a hatchery is growing out some lmb to the 1.5 to 2.5lb range to sell, do most hatcheries expose their feed trained lmb to forage? Or are they selling these larger sized lmb from an environment with feed only? What is the standard practice in the hatchery business when raising larger sized feed trained lmb? I would think the hatcheries would exchange information as to what works best when it comes to stocking customers ponds when selling the larger sized lmb? Exposing feed trained lmb to forage, bg, minnows, shad. Would this be the norm? Or not?
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 11/14/18 12:26 PM

From what I know. Hatcheries do not raise 2 lb LMB in the lab for sale to the general public - way to expensive. They do a variety of things along the lines of growout in ponds with feeding and some with natural forage and some mix of both. 12 inch , 1 lb LMB stocker fish are not easy to located from good sources. They can be arranged in advance in my experience.

So the question was - " So, if a hatchery is growing out some lmb to the 1.5 to 2.5lb range to sell, do most hatcheries expose their feed trained lmb to forage? Or are they selling these larger sized lmb from an environment with feed only?"

What I have found is the LMB are feed trained up to a few inches and then placed into ponds with existing forage. They are feed pellets after that. I have seen a few times that the small LMB are put in ponds with only feeders but that is a small portion of the time. My guess is it varies by hatchery based on need and demand. Others need to chime in with their experience.


To be clear the issue we are discussing ( studies above) is the use of small(< a lb.) feed trained only LMB stocked into a pond with an existing predator fish (LMB) population. Glad to discuss any situations I just don't want to give anyone the wrong impression or data.
Posted by: Bill Cody

Re: Observation on Feed Fed Largemouth Bass - 11/14/18 07:55 PM

Quote:
I would think the hatcheries would exchange information as to what works best when it comes to stocking customers ponds when selling the larger sized lmb?


Good sense would agree with your assumption but reality is fish farms tend to be very protective of their farming methods to try to stay financially ahead of their competition; a strong financial stimulus.

A local farm near me raises larger LMB exclusively on pellets for the oriental food market in Canada. These fish likely get occasional natural pond food items during their grow out period, but natural foods would be rare in a pond with a high density of LMB. The farm does sell some of these larger bass for pond stocking.
Posted by: Jim Wetzel

Re: Observation on Feed Fed Largemouth Bass - 11/15/18 09:53 AM

The rearing of LMB to 1.5 to 2.0 lbs is expressly what I am involved in. The technology is relatively easy to command once you have in place resources needed to engage in pond culture and ideally capacity to hold fish at high density during feed training and immediately prior to marketing. From what I have been seeing, fish in a pond feeding well on pellets in a pond setting put little or no effort into going after natural forages. It is not unlike what goes on in a stream setting where some bass exhibit a strong preference for fish while others go mostly for crayfish. Search images and likely experience impacts on handling time help a fish decide where to invest feeding effort. It is pretty easy to see this stuff with groups of bass that are very easy to observe and distinguish.
Posted by: Jim Wetzel

Re: Observation on Feed Fed Largemouth Bass - 11/15/18 09:58 AM

Originally Posted By: ewest
From what I know. Hatcheries do not raise 2 lb LMB in the lab for sale to the general public - way to expensive. They do a variety of things along the lines of growout in ponds with feeding and some with natural forage and some mix of both. 12 inch , 1 lb LMB stocker fish are not easy to located from good sources. They can be arranged in advance in my experience.

So the question was - " So, if a hatchery is growing out some lmb to the 1.5 to 2.5lb range to sell, do most hatcheries expose their feed trained lmb to forage? Or are they selling these larger sized lmb from an environment with feed only?"

What I have found is the LMB are feed trained up to a few inches and then placed into ponds with existing forage. They are feed pellets after that. I have seen a few times that the small LMB are put in ponds with only feeders but that is a small portion of the time. My guess is it varies by hatchery based on need and demand. Others need to chime in with their experience.


To be clear the issue we are discussing ( studies above) is the use of small(< a lb.) feed trained only LMB stocked into a pond with an existing predator fish (LMB) population. Glad to discuss any situations I just don't want to give anyone the wrong impression or data.



State / government owned hatcheries typically have much higher production costs for just about everything when compared to private producers. Private producers can produce 2 lb food fish at a profit while state hatcheries have to suck the taxpayers wallet raise a similar product. I no longer use the term hatchery unless dealing with an operation that specializes in actually hatching eggs and rearing early life stages. Government supported operations most likely to fall into this category.
Posted by: TGW1

Re: Observation on Feed Fed Largemouth Bass - 11/15/18 04:10 PM

Four years ago when I discovered Bob Lusk, The Pond Boss Conference and this forum, I learned of feed trained lmb. I saw exceptional growth with native or northern lmb. I understood Bob lusk and Richmond Mills may have been primarily feed lmb, Gregg Grimes feed trained lmb along with high forage fish numbers. I am still learning, Thanks guys. Jim, please keep us in the loop.
Posted by: Bill Cody

Re: Observation on Feed Fed Largemouth Bass - 11/15/18 07:26 PM

Members and readers, we are still looking for some pictures and information of how big your pellet fed largemouth bass have grown in your ponds. I am especially interested in how your LMB are doing if you are feeding the Aquamax Largemouth Bass nuggets. Those bass should be easily adding one pound of body weight each year.
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 11/16/18 11:50 AM

Yes Bill we need that and any and all info on LMB in a pond with only feeding (no substantial reliance on natural forage). Does anyone have a pond like that?
Posted by: bassmaster61

Re: Observation on Feed Fed Largemouth Bass - 11/16/18 12:50 PM

We have been feeding Aquamax MVP to the LMB we stocked in early June 2017. They weighed 1-1.25 lbs. each and were feed trained when stocked. We caught several out of that small 1.6 acre BOW this last season that weighed in excess of 3 lbs.

However, this pond also has lots of natural forage and we have been hoping these stockers would take advantage of that. Not sure if they have been able to adapt to non-pellet live food or not.

That would mean that some of these fish have gained 2 lbs. or slightly more in 18 months.....4 of those months were in winter when i would imagine very little LMB feeding or growing is going on here in the Midwest....not a bad result in that amount of time IMO!

This next season we will get back into recording relative weight data in a consistent manner so my observations will have more numbers and statistics behind them. BM61.
Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 11/26/18 02:37 PM

Originally Posted By: ewest

Yes there are waters that need nothing and can support over a thousand lbs of fish per acre. There are also a lot that can only support 50 lbs per acre with out help.


I would think that BOWs supporting only 50#/ac are as rare as BOW's that support over 1000#/ac. The vast majority will fall between 120 and 350, where the most outside this range will be more than 350. The tendency for all BOWs is to increase in primary production over time.

Just curious, is 1000#/ac an objective?

I've said this this before. Feeding is a way to have the equivalent of more water. If one has a 1 acre BOW that supports 250#/acre then feeding so it supports 1000# is like having 4 acres that support 250#/acre. The difference? The fed pond that supports 1000#/acre is much more difficult to manage. It requires far more attention to water quality.

If the problem is skinny fish ... harvest fish. If the problem is the fishing isn't good because there aren't enough of them ... then feed and harvest many more fish.

Originally Posted By: ewest

The biggest problem is skinny fish and the easiest way to efficiently fix that is more food and harvest. Total population mgt is not about if you can grow a few big fish as that is common in non-managed low nutrient ponds as well. In most BG/LMB ponds supp. feeding of BG is very efficient and mostly results in better conditioned populations when used in connection with proper harvest.


A fish population quickly fills the carrying capacity. The benefits disappear after a year or two. So I agree with the condition that one MUST harvest to solve the skinny fish problem, even when the fish are fed. The problem isn't enough food, its enough food to go around. So harvest is the only long term solution for skinny fish while feed is viable long term solution for more carrying capacity.

Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 11/26/18 02:54 PM

Originally Posted By: anthropic
While it may be true that a pond with 150 lb of LMB can grow equally very large fish as a pond with 500 lb of LMB, wouldn't the latter grow about three times as many?


Yes, provided the harvest effort per acre is proportionate. In other words, the number of LMB one needs to cull will be three times as many. If one fails to perform 3 times the harvest or if a self sustaining balance doesn't exist. The BOW with 500 lbs of LMB has smaller LMB.

I would however think, that in a sustainable system, that 150 lbs/ac of LMB reflects well above average fertility. If one wanted 500 lbs/ac of LMB, he would also need a standing weight of around 1500 lbs/ac of BG and they would need to produce 2500 lbs/ac of BG annually just to sustain the biomass of LMB. Everything would need to be perfect. If one wanted 500 lbs of LMB/ac, it would be far cheaper to stock only feed trained LMB (no BG that would compete for LMB feed) and just feed them. In that scenario, FT LMB would excel and reproduction would stunt.
Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 11/26/18 04:36 PM

Originally Posted By: bassmaster61
Eric's info is kind of a bummer since the studies show that stockers are not very good at getting on natural forage.


bassmaster61,

just a couple of thoughts.

Based on the feed rate and the gain of the your FT LMB, I would think a portion of the feed has been going to BG. Also, if your FT LMB are not foraging, you would need to increase feed to keep them growing. Long term, I would think some would adapt to forage particularly if you maintain the current rate of feed. Those that do not adapt might begin to develop less RW than those foraging which might cue you as to which to cull. Or you might increase feed rates to keep them growing. Don't know much about feeders capablilities but if you could feed large pellets that most BG would have difficulty swallowing, this might help ensure that the food adds weight to the LMB.

Quote:
We will see what happens in our pond. Feeding fish is an experiment for us and if we start catching a decent number of large stockers on standard tackle next year I will consider it a success. But just in case, I am tying a few flies that look like Aquamax MVP pellets.....BM61.


I think LMB might respond similarly to CC. When feed is curtailed for a short period, they might bite more readily.
Posted by: Bill Cody

Re: Observation on Feed Fed Largemouth Bass - 11/26/18 07:32 PM

jpsdad - Thanks for the interesting insightful experiences and thoughts about your pond with feed trained LMB and fish management.
Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 11/26/18 08:28 PM

Originally Posted By: Bill Cody
jpsdad - Thanks for the interesting insightful experiences and thoughts about your pond with feed trained LMB and fish management.


You mean the 500#/acre LMB only pond fed only feed? Or the 500#/acre of LMB fed 2500#/acre of BG annually? Actually, I don't like either of those ideas.

The feeding benefit has mathematical relationships. If 3 lbs of feed makes one pound of BG what will cost to grow 1 lb of LMB? How much it costs I suppose doesn't really matter. But it comes with its accompanying commitments and in the end the key to whether it was and is worth it lies in whether it delivers what one was promised and expected.
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 11/27/18 01:49 PM

Originally Posted By: jpsdad
Originally Posted By: bassmaster61
Eric's info is kind of a bummer since the studies show that stockers are not very good at getting on natural forage.


bassmaster61,

just a couple of thoughts.

Based on the feed rate and the gain of the your FT LMB, I would think a portion of the feed has been going to BG. Also, if your FT LMB are not foraging, you would need to increase feed to keep them growing. Long term, I would think some would adapt to forage particularly if you maintain the current rate of feed. Those that do not adapt might begin to develop less RW than those foraging which might cue you as to which to cull. Or you might increase feed rates to keep them growing. Don't know much about feeders capablilities but if you could feed large pellets that most BG would have difficulty swallowing, this might help ensure that the food adds weight to the LMB.

Quote:
We will see what happens in our pond. Feeding fish is an experiment for us and if we start catching a decent number of large stockers on standard tackle next year I will consider it a success. But just in case, I am tying a few flies that look like Aquamax MVP pellets.....BM61.


I think LMB might respond similarly to CC. When feed is curtailed for a short period, they might bite more readily.


Guys look for an article in the next PB mag on feed trained fish.

Feed trained LMB stockers are only a problem when stocked into a system with an existing fish population ( adult LMB and others) that do not rely on feed (natural forage). They can adapt but are at a competitive disadvantage for a while. This may increase mortalities (a stocking/balance issue) and reduce growth.
Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 11/27/18 03:44 PM

Eric, would it be helpful to place new feed trained LMB stockers in a forage pond full of natural forage, particularly CNBG, for a week or two? No good long term due to overcrowding, but maybe they'd get the idea faster than just being thrown into the main BOW.
Posted by: Jim Wetzel

Re: Observation on Feed Fed Largemouth Bass - 11/27/18 04:30 PM

Limitations of feed-fed LMB may not be just a function of learning curve. The physiology / morphology may need to change as well. Latter may take more than a few weeks.

Should be easy to find publications supporting morphological changes of sunfish as a function of prey type. From what I have seen, it is likely the changes to LMB are likely to be just as pronounced.
Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 11/27/18 06:59 PM

Originally Posted By: Jim Wetzel
Limitations of feed-fed LMB may not be just a function of learning curve. The physiology / morphology may need to change as well. Latter may take more than a few weeks..


What are your observations as to morphology?


Originally Posted By: Jim Wetzel

Should be easy to find publications supporting morphological changes of sunfish as a function of prey type. From what I have seen, it is likely the changes to LMB are likely to be just as pronounced.


I know of one on OSS. I haven't read it but had assumed these morphological changes occur over a few generations. I suppose also that offspring of varying morphology are always in the population, those with morphology best suited for the most abundant prey have more reproductive success and quickly dominate.

Nobody has mentioned the impact of artificial selection at hatcheries with respect to feed training. At least some hatcheries, perhaps most by now, feed brooders prepared feed.

While epigenetic effects would likely subside after a generation or two, one has to wonder what they might be.
Posted by: anthropic

Re: Observation on Feed Fed Largemouth Bass - 11/27/18 09:44 PM

Justin Stane told me that he can identify LMB that focus on artificial feed just by looking at their coloration. I think (may be wrong, hopefully somebody will correct me if so) he meant that they are less well camouflaged. Pellets are easier to sneak up on than CNBG!

Whether they pass along this trait, I don't know. If so, would be a case of de-evolution, the loss of genetic information when doing so confers a survival benefit of some sort in a particular situation. Eyeless fish & amphibians in caves are a good example.
Posted by: TGW1

Re: Observation on Feed Fed Largemouth Bass - 11/28/18 08:17 AM

Eric brought up some possible problems when adding FT LMB to an existing fish pond where feeding the fish did not exist. And possible problems with fish population balance. I can see that. But for me the additions of FT LMB was for introducing northern genetics to an existing Florida strain lmb/bg pond. Improving the bite is the goal and I needed some lmb in or near the same size. The only ones that were available were feed trained. So, I stocked them 6 months ago. I feed them aquamax lmb feed and they are feed right beside the TH feeders that feed my cnbg. My attempt to improve their adjustment to a new home where the natural food (bg) was right there where they get the artificial food. I try to hand feed the lmb at or around the same time the feeders throw MVP to the bg. I can say the FT lmb are really looking good. RW are above 100% and very healthy looking and are easier to catch on rod and reel. I am very happy with my Florida Lonestar legacy lmb but they can be harder to catch sometimes.

We fin clipped the FT lmb making it easier to recognize them.
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 11/28/18 11:05 AM

Originally Posted By: TGW1
Eric brought up some possible problems when adding FT LMB to an existing fish pond where feeding the fish did not exist. And possible problems with fish population balance. I can see that. But for me the additions of FT LMB was for introducing northern genetics to an existing Florida strain lmb/bg pond. Improving the bite is the goal and I needed some lmb in or near the same size. The only ones that were available were feed trained. So, I stocked them 6 months ago. I feed them aquamax lmb feed and they are feed right beside the TH feeders that feed my cnbg. My attempt to improve their adjustment to a new home where the natural food (bg) was right there where they get the artificial food. I try to hand feed the lmb at or around the same time the feeders throw MVP to the bg. I can say the FT lmb are really looking good. RW are above 100% and very healthy looking and are easier to catch on rod and reel. I am very happy with my Florida Lonestar legacy lmb but they can be harder to catch sometimes.

We fin clipped the FT lmb making it easier to recognize them.


I would expect good results (for your goals) from your approach as you are feeding. I have seen this work many times and it has worked in controlled studies.
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 11/28/18 11:10 AM

Originally Posted By: anthropic
Eric, would it be helpful to place new feed trained LMB stockers in a forage pond full of natural forage, particularly CNBG, for a week or two? No good long term due to overcrowding, but maybe they'd get the idea faster than just being thrown into the main BOW.


Yes that has worked in studies and in practice - see the upcoming article. If you are thinking about this approach seek out a good hatchery that raises the stocker fish first on pellets (most do so for economic reasons) that then places them in ponds with both natural food and pellets for rearing until sale. This has been shown to make a big difference. Still need to habituate them to predators before or in conjunction with stocking.
Posted by: ewest

Re: Observation on Feed Fed Largemouth Bass - 11/28/18 11:15 AM

Originally Posted By: jpsdad
Originally Posted By: Jim Wetzel
Limitations of feed-fed LMB may not be just a function of learning curve. The physiology / morphology may need to change as well. Latter may take more than a few weeks..


What are your observations as to morphology?


Originally Posted By: Jim Wetzel

Should be easy to find publications supporting morphological changes of sunfish as a function of prey type. From what I have seen, it is likely the changes to LMB are likely to be just as pronounced.


I know of one on OSS. I haven't read it but had assumed these morphological changes occur over a few generations. I suppose also that offspring of varying morphology are always in the population, those with morphology best suited for the most abundant prey have more reproductive success and quickly dominate.

Nobody has mentioned the impact of artificial selection at hatcheries with respect to feed training. At least some hatcheries, perhaps most by now, feed brooders prepared feed.

While epigenetic effects would likely subside after a generation or two, one has to wonder what they might be.


Very interesting topic and we have discussed it in prior PB articles. Bob was doing an article that several of us provided info on the topic for but not sure he has used the article yet. Here is a bit on the topic wrt lepomis sunfish. Keep in mind that all my comments in this thread are short term effects on LMB stocking ( a few mths but less than a year).

In these articles plasticity = adaptive behavior (adaptation) = phenotypic plasticity which can lead to morphological changes .

The Effect of Vegetation Density on Juvenile Bluegill Diet and Growth in the Journal of Freshwater Ecology 2012, 1–11 by Daniel E. Shoup , Michael A. Nannini & David H. Wahl discuss a number of their thoughts which are set out below.
At the start the authors noted that the role of vegetation density and its influence on juvenile bluegill diet and growth remains unclear. Even after the many studies that exist. They acknowledge much disagreement in the literature about how vegetation density affects foraging results and thus growth of juvenile bluegill. Several studies have found reduced foraging return for bluegill when they forage in structurally complex habitats, whereas others have found that bluegill growth was unaffected or even increased when foraging in complex environments. However these studies were with predators present. That is not the case when a typical bluegill or other forage base is first started in a new or renovated pond without predators.
In the Shoup et al study eight experimental 0.4-ha ponds (one acre with a mean depth of 1m) were used to evaluate the effects of habitat complexity on growth of small bluegill. Each pond was stocked with 15 kg of young-of-year bluegills (30–50 mm total length, approximately 20,000 fish per pond) to produce a realistic density for small ponds. The ponds contained varying amounts of vegetation (plants) and no predators.

The result was - by the end of the experiment, bluegill from the low vegetation treatment ponds were significantly longer – twenty (20%) percent than bluegill from the high vegetation treatment ponds. These results suggest that bluegill chose to forage in a vegetated habitat even in the absence of predation risk, resulting in reduced growth. The question is why and what caused the bluegill to stay and forage in the plants even when that was not optimum for growth and energy usage (energetics).
Because piscivorous fish were not present in the study ponds used by Sloup et al, it was surprising that bluegill foraged so heavily in the vegetated habitat. Either bluegill cannot accurately assess predation risk or some other mechanism causes bluegill to forage in vegetated habitat. The propensity of bluegill to forage in vegetated habitat could be genetically linked or related to phenotype . In both cases, fish would not be expected to alter their habitat use in response to the absence of predators over short time scales. Bluegill may also select habitat due to temperature preference rather than foraging return highlighting the potential for mechanisms other than predation risk.
The authors’ bottom line - additional research is needed to determine the pervasiveness of these behaviors and the underlying mechanisms.
One area I wish the study would have addressed in more detail is phenotypic plasticity. That is the ability of an individual or population to change due to environmental influences. Can environmental conditions during early development shape individuals’ phenotypes so they become more adaptive to the conditions they encounter? Were the long bluegill that fed in open water that way because longer fish can swim better in open water and were the shorter bluegill that way because being short allows them to maneuver around the weeds better? Plasticity has been shown to effect sunfish (Lepomis) shape, feeding and behavior in some cases.


Genetic relationships among pumpkinseed
(Lepomis gibbosus) ecomorphs in freshwater
reservoirs of Portugal
Introduction
Morphological divergence in the form of trophic or
habitat polymorphism has been noted in a number of
freshwater species and occurs most often as a result of
low interspecific competition among cohabiting species
and high intraspecific competition within individuals
of the same species (Smith & Sku´ lason 1996).
The time span over which a species diverges into
distinct ecomorphs can vary, however, making it hard
to interpret if the differences have arisen as a result of
sympatry (i.e., within the same geographic range) or
had evolved in allopatry (in different geographical
locations) prior to secondary contact (Rundle &
Schluter 2004). A further complication is that morphological
diversification can also occur rapidly
among co-occurring conspecifics as a result of phenotypic
plasticity and ecological opportunity (Sku´ lason
& Smith 1995). This response is particularly
common for species in deglaciated environments and
in species-poor communities with abundant and
unexploited resources (Smith & Sku´ lason 1996), but
is also a characteristic of expanding and invasive
species (Yonekura et al. 2007; Pilger et al. 2008).
Therefore, introduced species provide good opportunities
to study the onset of contemporary evolution via
means of such rapid diversification (Stockwell et al.
2003).
As a group, Centrarchidae have been highly
successful in adapting to changing environments,
showing a high degree of phenotypic polymorphism
in both their native and introduced ranges (Robinson
et al. 1993; Hegrenes 2001; Brinsmead & Fox 2002;
Gillespie & Fox 2003; Yonekura et al. 2007; Pilger
et al. 2008). Introduced bluegill (Lepomis macrochirus)
populations in Japan are extremely efficient in
exploiting resources in both littoral and pelagic
habitats of lakes and reservoirs (Yonekura et al.
Ecology of Freshwater Fish 2011
Printed in Malaysia Ć All rights reserved
_ 2011 John Wiley & Sons A/S
ECOLOGY OF
FRESHWATER FISH
Bhagat Y, Wilson CC, Fox MG, Ferreira MT. Genetic relationships among
pumpkinseed (Lepomis gibbosus) ecomorphs in freshwater reservoirs of
Portugal.
Ecology of Freshwater Fish 2011. _ 2011 John Wiley & Sons A&#8260; S
Abstract – High levels of morphological differentiation have been found
among pumpkinseeds (Lepomis gibbosus) occupying four habitat types in
Portuguese reservoirs. To investigate the underlying mechanism behind the
phenotypic differentiation among ecomorphs, we used six microsatellite
markers to assess patterns of genetic differentiation among and within eight
naturalised reservoir populations. Greater genetic differentiation was seen
among reservoir populations than within reservoirs (FST > 0.041,
P < 0.002). structure analysis revealed the presence of two distinct
genetic groups among the set of eight reservoir populations. However, an
analysis of co-occurring forms that were identified a priori by their
respective habitats was consistent with a single panmictic group,
suggesting that morphological differentiation has arisen in sympatry (i.e.,
within a reservoir, postintroduction). The observed relationships within and
among reservoir populations, combined with the timeframe of ecomorph
divergence, suggest the strong likelihood of phenotypic plasticity as the
underlying mechanism of diversification in the introduced pumpkinseed.


Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 11/28/18 11:47 AM

Tracy is having good success catching the FT LMB while others with FT LMB have expressed concerns regarding their own experience with catch rates. I think it may be interesting to understand the extent to which feed rates affect fishing effort for FT LMB.

Where it comes to FT LMB. It seems to me that one should have a goal as to growth and also as to whether one wants to wean them from feed. To be sure, one can grow LMB more cost effectively on feed than he can on BG. It takes a lot of BG to make 1 LB of LMB but $3 of feed can make the same gain on a small LMB. $3 per pound is very cheap for carnivore production. From the stand point of feed rates, though, one should consider the combined need of maintenance and growth. As starting point, I would propose 1.25#feed/#LMB-year as maintenance and 3#feed/#LMB_gained for growth. Take # to mean lbs not number.

#to_Feed = #LMB*1.25 + #LMB_gain_goal * 3

From this formula, it is easy to see that feed loses efficiency as the fish grow in size and for a given feed rate, eventually it takes all of the feed to maintain the biomass, that is unless, there is some mortality of the FT-LMB. A complete plan would then be to recruit FT-LMB annually and harvest when a target weight is a achieved or a time in pond is achieved. Eventually, a harvest is required if RW and growth is to be good for a fixed feed rate. A plan can easily be put together in an spreadsheet and when one does this, the goals should be met and the expectations satisfied.

Now back to fishing effort. The FT_LMB need to be maintained. If only maintained one can still expect growth in the length of FT_LMB. This means under maintenance alone, RW will decline year after year. This further means that growth must be factored in (for a long term plan)and it is this variable that I think to be most relevant to fishing effort. Under maintenance alone, the fish would be HUNGRY all the time. The key then is striking the optimum balance. How much one feeds beyond maintenance will have the greatest impact on how well they bite. Ideally, one wants acceptable growth and acceptable fishing effort but these two properties occupy opposing sides of a balance.

RW may be the most appropriate indicator of optimum feed rates in the recreational setting. To be sure, high RW will achieve large weights sooner and will be more efficient if weight alone is the objective, like when growing them for market. But who wants a feedlot where the fish are difficult to catch? Perhaps a goal of RW of 100 to 110% is a good goal for the recreational setting but real data could allow one to understand a range of what to expect for a given plan.

Where forum members are keeping records and in particular fishing effort we could gain some insights into this dynamic as it applies to the success of a recreational LMB feeding plan. I would suggest that an appropriate measure of fishing effort for FT_LMB would be Num_Fish/(Density * HR) . Density is the Number of FT_LMB per acre. One needs a means of identifying FT fish as Tracy did by fin clipping.

The Num_Fish/(Density * HR)isn't likely the only factor affecting availability of catchable fish. Also the number of hours fished reduces catch rates per hour as once a fish is caught it will not likely be caught again the same day. So the most appropriate data will limit the fishing time of an outing to some function of the number of FT LMB in the BOW.


Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 11/28/18 12:58 PM

Originally Posted By: ewest
The question is why and what caused the bluegill to stay and forage in the plants even when that was not optimum for growth and energy usage (energetics).


There is substantial evidence in the literature that habitat complexity increases standing weights. Generally, it is thought that this arises from an increase in available foods where plants, brush, etc. provide substrate for food organisms. This finding seems to challenge those findings. One possible explanation deals with the environmental factor of space and perhaps even the perception of space. Perhaps the BG were exhibiting territorial behavior and the presence of structure may have reduced the limiting territorial requirement of space and allowed more individuals to survive.

More measures beyond length might be instructive. For example, standing weights, relative weight, mortality rate, etc. It is complex.

Originally Posted By: ewest

One area I wish the study would have addressed in more detail is phenotypic plasticity. That is the ability of an individual or population to change due to environmental influences. Can environmental conditions during early development shape individuals’ phenotypes so they become more adaptive to the conditions they encounter? Were the long bluegill that fed in open water that way because longer fish can swim better in open water and were the shorter bluegill that way because being short allows them to maneuver around the weeds better? Plasticity has been shown to effect sunfish (Lepomis) shape, feeding and behavior in some cases.


Good points. I wonder also whether different prey types and their corresponding nutritional value may play a role. For example, do the open water organisms provide more of nutrition needed for bone growth?
Posted by: jpsdad

Re: Observation on Feed Fed Largemouth Bass - 11/28/18 02:07 PM

Is it difficult to feed train LMB that have relied on natural forage for a couple years (~12" TL)?

If not, would they prefer feed over natural food when release back to their native water or vice versa?