Pond Boss Forums INTRO Questions & Observations What makes exceptional trophy lakes different?

Eric, this interests me for a number of reasons but in essence it depends on % of lipids in the 180 RW LMB. So I wonder how much of the additional 80% is fat. Also how much water content is within the fat tissues? Lipids are super high in energy content and so a couple of things come to mind. First, does this in part explain why the intrinsic FCR worsens in cold water? By this I mean that if the LMB preferentially stores energy above its maintenance in the form of lipids instead of protein (which in muscle contains a lot of water) then weight gained will be less even though the gain of energy (of the LMB) is relatively the same. In that sense conversion on a energy basis could be better than the gain in weight would otherwise suggest. If that extra 80% were fat and if that fat contained only say 30% water then (.70 * 80/180) 31% of the LMB would be lipid and this would represent a huge store of energy that could take the fish through very lengthy periods without consuming.

Here is an example. Using average daily temperature as the water temperature, I compute that Dixon Lake LMB needs 4.93 lbs of BG per pound of LMB per annum for maintenance. Since BG are 4,186 J/Wet gram and lipids average ~37,000 J/Gram then we can calculate the weight of lipid required for energy per pound of LMB (4.93*4186/37000 = .55 lbs. If the LMB is 31% lipid then it has stored in its lipids enough energy to supply .31/.55 =56% of its annual energy requirement. Pretty amazing when you think about it. Dixon Lake LMB may need less than 4.93 lbs of BG if I am overestimating the temperature. IOWs they may inhabit cooler water than surface water which will vary around the average daily air temps each day. From this perspective I may have understated the reserve in terms of % of annual energy needed.

Imagine a 7.76 lb 23.3 standard weight LMB having turned the corner for consuming 1 lb trout could gain 80% in weight over the winter period by consuming 26 1 pound RBT. From November 15th to March 31st this would take one 1 lb RBT every 3.7 days.

Thank you for the input. Honestly, 1 to 2 lb RBT are very large for LMB consumption and I was skeptical of it. Was just working the numbers provided. 10" RBT are absolutely ideal for >20" LMB and if they are comprising =>25% of stocking in number then I could see 25% being the LMB mortality number. A 10" RBT is not an insignificant meal even for 28" LMB. The stocking sizes mentioned are a wider range of lengths and weights (ranging .37 lbs to 1.5 lbs). The 10" RBT are sufficient to supply enough food in a single serving to inhibit a second consumption on the day of stocking. It would be a good strategy to use 10" RBT as decoys on stocking day to take pressure off of the consumable, shocked, and disoriented but larger RBT. The loss on stocking day would be a smaller weight of fish that are cheaper to produce.

Esshup, where did you get your number for lake size? I ask because originally I got a number from Google maps measurement tool of ~62 acres. I went with 68 acres because I read it in an article.

I am learning a lot from this thread - keep up the good efforts. Vulnerability of prey I think has a lot to do with how predators choose prey. Fishery energetics have a lot to do with with growing fish.

I think the post indicating Dixon Lk was 600 ac was a mistyping error. The lake I think ranges from 60 to 70 acres depending on water level; maybe even less than 60 ac during drought conditions. Many of us know how much pond surface area depends on water input and drought.

jpsdad, I fat fingered the lake area. It is around 60 acres like you said, but when there was more rainfall in the area it usually was around 70 acres. While I can't find any current stocking data as to the frequency, when the bass were growing the biggest, they were stocking anywhere from 2,000 to 4,000 pounds of trout every 2 weeks from late November to sometime in April, which really helped their body condition to prepare for spawning. Look at the LMB that was named Dottie. Look at her weight when she finally died, and how old do you think she was?

The best fish nutritionist I know developed Purina's largemouth bass pellets. He did so by studying the body content of RT and mimicking the nutritional contents. That says enough for me, plus they work very well in actual use.

I don't know esshup but will take a stab. I think Dottie started life like most LMB which have good but not maximum growth on a diet of BG. So maybe couple of years to reach 12" . There after I see Dottie growing about 1 lb a year until reaching 20" inches and 5lbs in weight. So at 5 lbs I estimate she was in her 6th year. Thereafter, the boon of winter consumption of 10" RBT allowed her to consume all the energy she cared to. Per Dr Swingle, LMB can grow maximally at 2 lbs a year so I will just use that number. 20 more pounds is 10 more years ... so ... maybe ... 16 years?

Guess I was wrong. Took some searching but I did locate Dottie's age at death. 14 years.

Dottie was 29.5 inches long at 14 years. To me, that is difference between Florida and Northern LMB. How long they grow in their lifetime. Even so there are a few notable Northern's in terms of length. Ohio's state record was 25 1/16" long and had a RW of 140. Kansas' state record was 28.5" long but was less than 80 RW. Wonder what its potential could have been or if was much larger in weight before finally being caught. Kansas' record is long enough to wonder if it might have had Florida genes. Length is really the only thing that keeps Dixon Lake LMB from growing even larger. There is a limit to how long and how fast they grow long. But for as long as they grow they can be 150 to 180 RW which packs a lot of pounds on their frames.

The RW is only an Alpha and Beta figure (formula) that fits what is know as Typical for a given species but does NOT allow for an unknown strain % of a fish that has FL and Northern genetics.
My point is the "80" is not relevant if a northern LMB chart was used and the genetic makeup was a possible % of both N and FL.
Same for the 150-180. I don't feel that's an accurate assessment of unknown genetics.
Lets go back to the KS record.. If that fish achieved 28.5", at some point, it had to be in 100% condition to achieve that length, yet an Alpha and Beta was used that was designed around typical for what?? Northern or FL strain?

So you bring up a good point. Should a person use a different RW charts/formulas for Florida's and Northerns?

But back to the point I intended. Consider just the KS and OH records. Presumably, both fish were northern LMB. The OH fish was relative to the KS fish short and fat. But the OH fish outweighed the KS fish. The KS fish is the only northern LMB that I have knowledge of that achieved 28". Given the two fish, and given the choice of one for propagation ... which should one choose? I think I would choose the KS fish because it had a very exceptional length that is uncommon for northerns.

A different case, a selection of shooters from a crop of young adults. How could one determine which fish devote more energy of the same consumption of energy to growing longer?

I would love to hold a 180 RW LMB some day. Maybe I will make a trip to Dixon.

But you completely missed my point. I think 150-180 RW has little to do with Florida or Northern genes. Fish can grow remarkably just consuming that extra fish that takes it over maintenance. Regularly getting an extra one every couple or three days will allow their RW to grow remarkably but after adulthood it isn't going to cause their length to grow remarkably. Being fat is just consuming a marginal amount more than the standard weight fish of the same length consumes.

Sometimes a picture paints a 1000 words. Florida genetics, I think, help fish put on more length at similar ages than Northern genetics do. So in Texas, the introduction of Florida genetics has had a significant impact on ultimate weights achieved. Same goes for CA and Biwa in Japan. Let's do a comparison of LMB that achieve different growth increments each year so also achieve different ultimate lengths in their 14th year. I have plotted Dottie and another LMB which could be either Northern or Florida that achieves a length of 25" (the same as the OH state record)



Below I plot two fish one of which grows to Dottie's length but only consumes enough to maintain 100 RW. The other is one which grows to 25" where for its entire life it is RW of 140. Both fish start at 1 lb at the start of their 2nd year. The fatter fish which achieves lesser length increments only has an advantage over the fish that logs larger length increments at std weight in the 3rd year. There after the effect of faster length increment gives the weight advantage to the fish that has greater increments in length. The reason is that standard weight is a power of length and the magnitude of the power is greater than 3 (weight is proportional to L^3.28). Small increments in length have profound influence on the weight of a standard weight fish. RW influence is more limiting being a linear proportion that seems to be bounded by 80% additional weight.



OK, So Dottie didn't grow at standard weight her whole life. But she probably logged something similar to standard weight growth until RBT became an important part of her diet. Below is plotted Dottie versus the 140 RW LMB that "only" achieves 25" at 14 years. When Dottie reached 20", she gained the ability to exploit the 10" stockers and so could pack on additional weight above the standard weight. This occurs beginning the 5th year of age. The maximum percentage weight growth increment will occur when the 10" stockers are most optimum energetically. It may not be the 5th year (as depicted) but a later year. Also, Dottie would not have maintained 156 RW throughout years 6 and 14. There would have been a ramp up and then a small decline after the peak was reached. In 2003 Dottie's RW was close to 180 but when last foul hooked in late March of 2006, her RW was "only" 156. It was the length increment of 2.25" that made the difference and added a little less than 4 lbs to her in spite of RW decline.



So I hope this expresses better what I was saying. Length increment and ultimate length are important parameters for genetic selection. Florida's seem to have an advantage there (just judging the difference Florida LMB have made in Texas). I think this is the most important attribute for ultimate weight. RW can be controlled by feeding forage but a fish's genetic predisposition to grow longer is desired and should be selected for no matter what the species or strain we are talking about. Weights alone can be a problem because environmental factors affect RW and environment isn't a genetic trait.

Just an update. Dottie died in 2008 when she was 14 years of age. She was 29.5" long at the time of death. So in 2006 when she was 12 years of age and then weighed 25 lbs she would have been close to 180 RW. To know for sure would have required a length measurement which did not occur at that encounter. Even so, her RW should have been between the range of 172-182.

So you bring up a good point. Should a person use a different RW charts/formulas for Florida's and Northerns?
If using this data as a tool to see which way from STD the health is, continue using it for both if you can confirm DNA, but these formulas were never intended to depict accuracy above (or below) a certain percentage. There are visual cues that identify a fish that is "non-standard" and by this I mean (in the case of the KS bass) it cannot grow to X length without achieving Y weight. What it weighs at the time you have it in captivity is only relevant if you knew all the reasons it was a supposed 20% below the assumed STD weight. Chances are, this falls under what most Biologists will tell you is the area of unknowns that we may never understand because either they have never been researched or research provided no answer.
These fish in question are brutes for a pretty simple reason.. they had the right genetics, the best forage with the least amount of energy expended to consume it under the best conditions for growth. The argument will be that these are not optimum conditions considering water temp in some cases. I'm saying there are many, many other factors involved that we may never understand, but the truth remains that these fish are "Non-standard". There is no way to predict this because we follow conventional wisdom in fishery management every day and it does NOT produce this result with any regularity. I don't want to deflate any of your assessment, somebody needs to research this.
My views come from some pretty salty sources, such as one of our hatchery managers that was instrumental in the share-a-lunker program. His number 2 is one of Dr. Willis's shining students. These are the guys growing the 5-6lb male LMB (northerns) that I've mentioned before. The funny part of the share-a-lunker program that has been explained to me is that the quality of eggs a female of huge proportions develop, also produce less fry % per number of eggs and deformation in fry is much higher. KS sends the 10lb+ females down the road for the remainder of their life being chased by anglers in public impoundments.
I say keep up the research, there is information yet to be found that some day may better answer the questions.

Snipe, I use a formula that I regressed from a length weight chart that was representative of Northern LMB. That said, all LMB are bass of the same species with some regional variation. IOWs the samples will vary by region from which the charts are derived. But when you think about it all LMB are similarly shaped and I think as long as one's yard stick is consistent then one can gain an understanding of how "fat" or how "lean" a bass is relative to the yardstick.

You mentioned:


So the question is ... which is cart and which is horse? I figure you have kids and have watched them go through growth spurts. When I observed this, I noticed that coincidentally their appetite to consume food also increased. So did they grow just because they spontaneously started eating more? OR did they eat more because they spontaneously started growing? Here is what I think about it. I think hormones are released at different stages that stimulate growth and when more of these hormones are present the greater the demand for consumption will be to support growth and this will be evident as increased consumption and correspondingly greater growth in weight. Furthermore, I think RW gets high because fish are consuming more than required to grow as much as their genetic predispositions allow them to in length. If length was simply a function of weight gained ... then fish wouldn't have very high RWs ... they would just grow in length more in line with the standard weight charts. We may not be able to agree, that is OK, I respect your opinion. If shared by your KS biologists, I respect that too.

A couple of years ago saw the Texas top 50 LMB at the TWPD website. I copy and pasted the contents of into excel and looked at it statistically. The data showed an average weight of 16.27 lbs, an average length of 26.57" and an average RW of 1.43 (per my chart). The data suggested that to have a good chance of making the Top 50, an LMB needs to be a minimum length of 25" and a RW >110. Now a 25" LMB at 110 RW will definitely NOT make the list. Takes a fatter LMB of smaller length in order to weigh enough. Plotted RW vs Ranking and Length vs Ranking the data showed that ranking is not tightly correlated with either RW or Length. IOWs one may not use Length as a predictor of ranking or RW as a predictor of Ranking. Even so, regression shows that ranking favor longer fish and fish of higher relative weight.

Notice that the limit of RW is around 180 just like it is in CA. There is no trout forage to support the larger fish and so only a small minority of the Texas fish have enjoyed such high RW as 180.



On the other hand, in Texas lakes, the RW of the top 50 LMB depended a lot on Length. In fact, Length explained 89.34% of the variation of RW. This must be environmental and represents the effects of competition and forage supply. Likely forage availability is most favorable to fish =< 25" in length. This contrasts with Dixon Lake where Dottie at ~ 28" had a RW in the neighborhood of 178. There in Dixon, forage availability doesn't seem to diminish for longer LMB like Dottie. One should keep in mind that it may be possible that none of the fish in Dixon have genetics as good as any that made the Texas Top 50 (which are the extreme examples of a much larger population undergoing less advantageous environmental conditions). Just saying ...

I think we are just looking at this from 2 different perspectives as I am not really disagreeing with what you have posted.
I think you are looking at more non-std size fish and I am considering std for the species.
I'm going to use SMB as an example: Micropterus dolomieu (Northern strain usually known as Dale Hollow strain) & Micropterus dolomieu velox (Neosho strain and a strictly river dweller).
AFS recognizes SMB as M. Dolomieu and the Alpha and Beta of STD RW is used for this species. The Neosho has no RW chart-yet-and there is yet a 3rd species that is not officially recognized yet but I think will be in the next 2-3 years.
The DNA testing has shown some radical variations amongst all 3 when crossed-just like Northern and FL LMB.
My view is if someone has a Northern strain SMB chart and uses it to calculate a neosho, or a cross of those, the numbers come out pretty ugly the bigger the fish is. This is happening with SMB fish farms that don't know where their brood stock is in that chain, I am finding it more and more each year.
My thoughts are that it's more likely to have F1 LMB at some point, or even possibly an F2 that exhibits more FL traits, and therefore, by the chart, shows numbers that are not accurate for the species, such as 180 RW for a fish of X length. I'm not sure if we could even calculate those numbers with proper DNA tests and probably why that number or chart has not been introduced.
It's not a cart before the horse deal, it has to be a peer agreed fact that the STD is objective where sub-species and other factors can screw that number in or out, especially when we don't know the genetics ratio.
Maybe I'm cutting hairs but for the 4 years I've spent DNA testing all of my brooder SMB, there's no more SMB showing up at 85-90 RW but look just fine.
I can 99% of the time, identify the fish by just color now at a much younger age.
I know that doesn't apply here and has no relevance but we have a Moderator on this forum that has experienced both sides of that genetic mix on SMB and has a clear story as to what I'm talking about.

Snipe, after your post, I think we are on the same page. What you are speaking of are morphological differences between strains. I will further mention that the shape of centrarchid fish change significantly as they grow. They begin as slender little things and as they age they become taller proportionally relative to their length. This is why the power factor exceeds 3 instead of just being 3 for every centrarchid. A power of 3.28 for LMB or 3.44 for BG exacerbate weight for longer lengths. Other fish like TP and carp are very nearly 3 because their shape doesn't tend to change much as they grow in wild populations.

As for whether 180 is too high for Florida strain LMB, this may be so. The problem is that I don't know of any data on the morphological differences between Florida and Northern LMB. It is probably worth deeper investigation. In the samples I referenced, all the CA and TX fish possessed Florida genetics and were intergrades of the two strains. One way to test for the differences would be to see if RW is also bounded 180 for Northern LMB of the greatest RW. If that RW limit is lower using the equation I employ then this would be evidence supporting that intergrade LMB have power factors greater than 3.28 (the number that fits the LMB chart I use). So far, the highest RW that I am aware of for Nortthern LMB is 140.

There are ways to test the various propositions. For example, if the proposition that Florida genes cause LMB to grow faster in length than Northern genes is true, then intergrades starting at the same length and weight would grow differently than Northerns on equal rations. To be true, the Florida interragrade length increment would have to be greater and it's RW would have to be less. If instead the morphology were different then the intergrades would gain RW but the length gained would be less than the Northerns. FWIW, I think either outcome is possible and it completely depends on whether the morphology is different.

I will emphasize that it is evident that intergrades at equal weight and length require more forage to be satiated than Northern LMB. Consumption is ultimately the overlying reason that intergrades grow faster. To grow bigger, there has to be more Consumption. Different morphology doesn't mean that Consumption will increase. On the other hand, greater rates of satiation leads to high RW and high RW can be confused with morphology. This is why I suggest that at equal weights and lengths ... a fixed and equal ration will make evident whether there is morphology difference or whether the difference is related to length increment and underlying effects of that underlying growth impetus has to increase consumption. It is an interesting question on a limited ration ... Will intergrade LMB prefer their shape or have greater length increment than Northern LMB.


Postscript

I wanted bring up just how unreliable standard weight charts are at predicting the weight of any particular fish. First thing. To create a chart, many samples are collected and then this data is regressed to a formula. The chart is the result of that formula.

Problems arise first because of sexual dimorphism. Females are shaped differently because of the production of gametes that are larger percent of their body weight and females consume more and build more body mass to support that effort. But the data includes both females and males and as they get longer the divide between what is normal at a given length for each sex widens. Consider a case where Females are normally 2 times the weight of males at the longer lengths. The equation (and the chart) will dissect the data and this will introduce a standard error as high as 33% just from sexual dimorphism. So imagine a "normal" female at RW 133 according to the chart ... but is really only RW 100. Now imagine a Female that 33% heavier than normal. This female will be RW 177 even though she is really only 33% heavier than average females of that length. For a species where females normally weight 2 times more than a male at a given length ... a female with RW of 100 may indicate very poor condition. .

In order to understand Northern potentials for length and weight I gathered up as many state records as I could find from northern states where lengths for the record was also recorded. The results are in the table below.



The order is descending by RW, please note the RW of CO and Ontario. Per the standard weight equation I employ, the RW seems to be limited to 170 for Northern LMB. This is very close to maximum RW achieved in TX and in Dixon Lake, CA. Also note the lengths attained. The maximum lengths are comparable to maximum lengths in Texas and even in CA. So this is causing my skeptical nature to kick in. Even though rate of growth in length would be a good trait to select for, maybe, there isn't much difference between Florida LMB and Northern LMB in terms of how long they are able to grow (notwithstanding strain variation of Northern LMB). So what else could be at play? Definitely, in Texas Northern LMB rarely (if ever) attain the maximum lengths attained in Northern states so perhaps LIFESPAN is the primary limiter ultimate weights of Northern LMB in Texas. Perhaps the Florida genes are helping LMB live longer in Texas and CA?

Also, I do wonder what was special about the CO and Ontario fish that allowed them to achieve such high RW ... they were indeed fatties. Did RBT play any role in their RW or perhaps a winter kill that affected a forage fish but not the LMB?

Also consider Michigan, they have two fish (15 lbs) larger than Texas was ever able to grow before Florida genes were introduced. The Michigan fish also attained lengths comparable to the Texas top 50. Maybe Texas Northern LMB just die young? Or possibly the Michigan strains have something special going on? Can we unlock more potential further north of Texas?

Returning to the Texas RW versus Length chart. which is reposted below. Why is length so inversely correlated with RW? Here is what I think. For a forage combination of BG and GSHD the most advantageous length for an LMB is 25". Forage supporting that 25" fish is all that supports it as it continues to grow in length. So it doesn't gain weight but just grows longer losing relative weight in the process of being supported by the limited food supply. So Texas fish top out within a pound or so of the average of the top 50 (16.45 lbs). Essentially the regression of the chart below is the RW of a 16.45 lb fish at various lengths. 16.45 lbs is the Texas wall that intergrade LMB cannot overcome without supplemental forage.

A short post.

Lol! Well played!

^^^ And just because I thought his "short" post was funny don't think I haven't read every word of this thread, because I have and some even twice. Tons of GREAT info!


Tell me if this sums it up somewhat simplistically; length (much like a man's height) is mostly genetic unless severely malnutritionad, fat is a nutritional thing. Ie - most men who are going to be 6'8" are born to be that way, same as a 28" bass. A tall AND FAT person had extra calories, the same as a long AND FAT bass. When I said "somewhat simplistically" I actually mean VERY simplistically.

I'm curious why in the table MI has 2 entries? is one a typo or are there 2 winners in MI for biggest fish?

wonder if one is supposed to be MO, dont see any data for MO.

Michigan has a tie for two LMB of the same weight. They were caught from two different lakes about 25 years apart. Missouri wasn't listed because I was not able to find the length.

One factor for the increased RW factor for state record fish is I think could have a lot to do with the gravid condition of the bass when caught. I have noticed that when fish weight is important to determine State Record fish the pictures of the fish appear to me that the fish was late stage gravid.

Mature egg mass for a 25" LMB I think could be I think 2 lbs maybe 3 lbs? .
Mature egg mass weight for a yellow perch ranges from 25%-30% of the female's normal weight. CB1 harvested an egg bound 15" YP that had a RW of 1.66. It was 15" long and weighed 3.26lbs.
Example if the 22.5" CO bass had Std Wt of 7.0 lbs and was close to spawning it's eggs could weigh 1.6-2lbs and without eggs the bass as a plump fish might weigh 7.0 lbs for a RW of around 1.4.

I hear the lead weight mass for some non-gravid walleye caught in a tournament can also reach 25-30% of the fish's normal weight.

Largest LMB I ever caught was 27" post spawn momma that we estimated at 11 to 12 lbs. So if we'd managed to catch her in peak gravid condition, you would estimate 13 plus lbs?

Exactly. Most of the RW ~ or > than 130 (where dates of catch were available) were caught in the Spring. One notable exception was the Ottawa fish which had a date of August. Not sure if that was the date the record was awarded or the date caught. Or possibly something else can explain, (eg lead weight, cold summer, rebuilt egg mass over summer, etc)