Pond Boss Magazine
https://www.pondboss.com/images/userfiles/image/20130301193901_6_150by50orangewhyshouldsubscribejpeg.jpg
Advertisment
Newest Members
Shotgun01, Dan H, Stipker, LunkerHunt23, Jeanjules
18,451 Registered Users
Forum Statistics
Forums36
Topics40,901
Posts557,097
Members18,452
Most Online3,612
Jan 10th, 2023
Top Posters
esshup 28,415
ewest 21,475
Cecil Baird1 20,043
Bill Cody 15,110
Who's Online Now
11 members (Dylanfrely, Angler8689, Sunil, esshup, jpsdad, azteca, BillyE, H20fwler, FishinRod, Augie, PRCS), 713 guests, and 264 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Page 1 of 3 1 2 3
Joined: May 2018
Posts: 1,882
Likes: 278
J
jpsdad Online Content OP
OP Online Content
J
Joined: May 2018
Posts: 1,882
Likes: 278
OK so as a heads up I will follow up with a paper I just read that will suggest that it isn't required. I am hoping to spark up some conservation about this topic and also hope to understand prevailing ideas and the extent to which they are pervasive. To be sure, only a few short months ago I would have told you that it is absolutely necessary and that low quantities of this size class would greatly reduce growth of fish > 21". The paper I read suggested that a mass size ratio of 100 to 1 of predator to prey (piscavorous relationship) is most appropriate in a sustainable ecosystem. For an 8 lb bass, the corresponding length of BG is between 4 and 4 1/2 inches or between 1/6 to 1/5 the length of the LMB. This 1/6 to 1/5 length ratio is predominate for all LMB weight classes studied (the largest which was ~ 15"). So not much data on trophies but these are rare and hard to collect data on.

Your thoughts and supporting arguments are welcome.

Last edited by jpsdad; 12/04/18 09:11 AM.

It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers


Joined: Jun 2015
Posts: 618
Likes: 73
Offline
Joined: Jun 2015
Posts: 618
Likes: 73
I am strictly going off memory here (from PB posts) but I've read about 1 to 3 ratio, regarding LMB length and the necessary gape size for larger prey fish. So the thinking is, a 12" LMB could handle up to a 4" BG. Add to that the thinking that, the LMB would expend less energy on chasing and eating ONE or TWO 4" BG than 4 or 5 two to three inchers.

So so how does the 100 to 1 mass size ratio correlate to the above?


"Politics": derived from 'poly' meaning many, and 'tics' meaning 'blood sucking parasites'.
Joined: Sep 2014
Posts: 3,668
Likes: 57
T
Offline
T
Joined: Sep 2014
Posts: 3,668
Likes: 57
I have no personal experience growing 8 lb lmb but I am working on it and may see it happen this next spring. Like Dr.Luke, I thought the lmb would take a larger meal when offered. In my pond I thought a 21" lmb would eat a 7" bg, Tp, lmb and an Res because they have to hunt less for food. My personal experience to date is that it will take a pond that is heavily stocked with different sized or aged forage unless there are only a few lmb in the pond.

If I need MORE 4" BG then I could see where feeding my bg may cause them to outgrow the size I need to feed my lmb.


Do not judge me by the politicians in my City, State or Federal Government.


Tracy
Joined: Oct 2018
Posts: 2,213
Likes: 514
S
Offline
S
Joined: Oct 2018
Posts: 2,213
Likes: 514
In electrofishing samples in a Res in west central KS we very frequently rolled bass with tails present extending from their mouths.
A prey of 1/5 the length would not be visible when swallowed. We had many bass with Gizzard shad with tails exposed. The most memorable was 1 of 22" that we extracted a 12.75" Shad from.
In gill nets we've had bluegill/crappie trapped in nets and Largemouth literally swallow the fish and be stuck until we run nets.
I'm no expert but I'd say when considering Bluegill as the main forage, 4" would be about what a 17-18" LMB would take, no problem. When you start getting into larger bluegill for larger bass you loose some return efficiency because gape size limits the seemingly "taller" BG that length is just not present for that size of fish. If Shad were present, the same LMB that can eat a max of 5" bluegill would probably be able to utilize a 12-13" shad or similar sized fish body shape wise.
It all comes to a head when you consider the effects of stocking shad and the higher potential for problems.
Dr. Luke's example of 35% may be spot-on as the Max size for Bluegill. If other species are present, that could very easily go to near 50% for some forage types.

Last edited by Snipe; 12/04/18 01:59 PM.
Joined: Mar 2005
Posts: 21,475
Likes: 264
E
Moderator
Hall of Fame 2014
Lunker
Offline
Moderator
Hall of Fame 2014
Lunker
E
Joined: Mar 2005
Posts: 21,475
Likes: 264
Send me the paper please.

Energetics formula can be done with all factors present. Science is not always in agreement with reality as there are significant deviations from the mean/norm - it does all depend.

Last edited by ewest; 12/04/18 04:11 PM.















Joined: May 2014
Posts: 3,861
Likes: 298
A
Offline
A
Joined: May 2014
Posts: 3,861
Likes: 298
I've seen 15" LMB trying to eat a 12" LMB that was obviously distressed, floating. They couldn't quite take it in, but I'd bet money a 9" would have been down the hatch.

Same with trout and shad and maybe TP. More fusiform shape, easier to swallow than CNBG/BG.


7ac 2015 CNBG RES FHM 2016 TP FLMB 2017 NLMB GSH L 2018 TP & 70 HSB PK 2019 TP RBT 2020 TFS TP 25 HSB 250 F1,L,RBT -206 2021 TFS TP GSH L,-312 2022 GSH TP CR TFS RBT -234, 2023 BG TP TFS NLMB, -160




Joined: Apr 2018
Posts: 1,220
Offline
Joined: Apr 2018
Posts: 1,220
Originally Posted By: anthropic
I've seen 15" LMB trying to eat a 12" LMB that was obviously distressed, floating. They couldn't quite take it in, but I'd bet money a 9" would have been down the hatch.

Same with trout and shad and maybe TP. More fusiform shape, easier to swallow than CNBG/BG.


All this being said makes me wonder why GSF aren't more readily accepted as a forage "addition" to the base. Their form makes them much easier for LMB to swallow. Not having the reproductive motsy of BG would keep them from getting overpopulated, but I know they get up to 9+ inches without much effort.


.10 surface acre pond, 10.5 foot deep. SW LA. The epitome of a mutt pond. BG, LMB, GSF, RES, BH, Warmouth, Longear Sunfish, Gambusia,Mud Minnows, Crappie, and now shiners!!...I subscribe!!
Joined: May 2018
Posts: 1,882
Likes: 278
J
jpsdad Online Content OP
OP Online Content
J
Joined: May 2018
Posts: 1,882
Likes: 278
Don't mean to keep you guys waiting for the paper ... but here it is ...
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5854328/

The source of data they analyzed was from field collected data from various authors. Some of the data was unpublished. Those data that were unpublished are source to state DNRs. The paper is basically a report of what sizes of forage different predators eat according to their size. Intuitively, it seems wholly plausible that fish will target the largest meal they can swallow. The energy is maximized in this scenario. Yet this size forage is actually far less taken by predators ... than forage we currently think to be energy negative. After reading the paper, it seemed plausible that predators like LMB actually benefit from prey less than 1/4 of their length. The most frequently taken range in the 1/6 to 1/5 length range ... but I am sure that these do not comprise the majority of the mass a predator eats. Even so, it is also clear that 1/3 length prey isn't either in the large and diverse samples of this paper. With some effort, I could extract some information from the graphics as to percentages of mass attributed to differing relative lengths ... for another time .. maybe.

I propose that willing readers here at the Pond Boss forum that harvest their bass might examine the stomach contents of their harvests to determine the lengths of prey their bass are eating. Feel free to post in this thread. I would help with getting the data into db form where it can be analyzed statistically, regionally, and according to other potentially relevant relations. Large fish > 20" might provide some information that is notably lacking in this paper. I'll refrain from any debate but it is worth asking the question. If you harvest a 24" fish and have lots of 7-8 BG, conventional wisdoms says that it will have them exclusively in its gullet. But if you find predominately 5" BG then it would seem to challenge convention.

To be sure, BG 1/3 the length of an LMB will fit in an LMB. If they don't predominate in the diet then there must be an explanation as to why. Possible reasons may be that they are less plentiful or that they are more difficult to capture unless sick or dying. These questions are worth asking because a BOW can produce significantly more weight of 5" BG than it can of 7"-8" fish.

Last edited by jpsdad; 12/07/18 09:15 AM.

It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers


Joined: Oct 2014
Posts: 6,080
Likes: 1
Offline
Joined: Oct 2014
Posts: 6,080
Likes: 1
I agree with this train of thought....It seems logical to me that the predator's mouthgap is the limiting factor. In other words, it's not how long the prey is, it's how "tall" it is that is the limiting attribute. The more fusiform the prey, the greater the length that is viable prey for any given sized predator.

Originally Posted By: Mike Whatley
All this being said makes me wonder why GSF aren't more readily accepted as a forage "addition" to the base. Their form makes them much easier for LMB to swallow. Not having the reproductive motsy of BG would keep them from getting overpopulated, but I know they get up to 9+ inches without much effort.


Mike,

I think one of the reasons GSF are not stocked as forage more frequently is their mouth gap is similar in size to that of an equivalent length LMB and therefore are direct competitors as predators for forage.

Just my 1 cent...

Last edited by Bill D.; 12/04/18 08:07 PM.

[Linked Image]
Be Brave Enough to Suck at Something New!
Joined: Apr 2002
Posts: 15,110
Likes: 478
B
Moderator
Ambassador
Field Correspondent
Lunker
Offline
Moderator
Ambassador
Field Correspondent
Lunker
B
Joined: Apr 2002
Posts: 15,110
Likes: 478
Great topic! The data and concept of reducing the optimum forage size as it relates to the predator size makes a lot of good sense to me. For LMB and several other piscivorous fish, I've always considered their catching and eating 'sunfish' 1/3 the predator length was not their most common (bass) food item. I've thought the larger sized food items were most commonly eaten usually as the weak or most vulnerable individuals encountered. Most frequent forage was smaller that what the predator was capable to swallowing. LMB as many predators are opportunists. Success of capture no doubt plays a big role in what predators most successfully eat.

Also handling time is longer for eating the maximum sized forage items. Handling time of predatory action due to chances of other predators stealing the food is considered a pretty important factor by fishery researchers. When I hand feed large softened sinking pellets to various species, I almost always see several individuals after the same piece of food which suggests "neighbors" are always willing to steal a food item (kleptoparasitism). So if when eating it takes one too long to get food swallowed, food can easily get stolen. It behooves predators to eat as quickly as possible which to me means eat the smallest yet largest items that can be swallowed quickly.

Last edited by Bill Cody; 12/04/18 08:26 PM.

aka Pond Doctor & Dr. Perca Read Pond Boss Magazine -
America's Journal of Pond Management
Joined: May 2018
Posts: 1,882
Likes: 278
J
jpsdad Online Content OP
OP Online Content
J
Joined: May 2018
Posts: 1,882
Likes: 278
Originally Posted By: DrLuke
I am strictly going off memory here (from PB posts) but I've read about 1 to 3 ratio, regarding LMB length and the necessary gape size for larger prey fish. So the thinking is, a 12" LMB could handle up to a 4" BG. Add to that the thinking that, the LMB would expend less energy on chasing and eating ONE or TWO 4" BG than 4 or 5 two to three inchers.

So so how does the 100 to 1 mass size ratio correlate to the above?


No the mass ratio is about 15 to 1. A 4" BG provides roughly 6.67% of a 12" LMB's body weight. It is enough to sustain 12" LMB for four days and if 12" LMB can eat one every day for 30 days he'll gain >30% of his body weight shocked !

Here is spreadsheet where you can play with the mass ratio:

Attached Images
LMB_LENGTHWEIGHT.xlsx (11.09 KB, 120 downloads)
Last edited by jpsdad; 12/04/18 08:29 PM.

It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers


Joined: Jan 2006
Posts: 16,028
Likes: 274
D
Moderator
Lunker
Offline
Moderator
Lunker
D
Joined: Jan 2006
Posts: 16,028
Likes: 274
Good topic. I've always accepted the 1/4 to 1/3 without really questioning it. From an energy expended versus calories obtained, it always made sense. However, thinking about it for the first time, It seems that one prey fish would take longer to break down versus two in the predators body.


It's not about the fish. It's about the pond. Take care of the pond and the fish will be fine. PB subscriber since before it was in color.

Without a sense of urgency, Nothing ever gets done.

Boy, if I say "sic em", you'd better look for something to bite. Sam Shelley Rancher and Farmer Muleshoe Texas 1892-1985 RIP
Joined: Oct 2014
Posts: 6,080
Likes: 1
Offline
Joined: Oct 2014
Posts: 6,080
Likes: 1
Originally Posted By: Dave Davidson1
Good topic. I've always accepted the 1/4 to 1/3 without really questioning it. From an energy expended versus calories obtained, it always made sense. .....


I agree, good topic. I now wonder whether it is really true that a big meal provides more calories vs energy extended. How much energy does a big fish use over the hours and hours it is struggling to swallow prey that is so large that it extends from its mouth vs quickly swallowing smaller prey?


[Linked Image]
Be Brave Enough to Suck at Something New!
Joined: May 2018
Posts: 1,882
Likes: 278
J
jpsdad Online Content OP
OP Online Content
J
Joined: May 2018
Posts: 1,882
Likes: 278
Originally Posted By: TGW1
... If I need MORE 4" BG then I could see where feeding my bg may cause them to outgrow the size I need to feed my lmb.


Tracy,

To be clear, I am not recommending that you deviate from your plan. This goes for everyone following a plan recommended by professionals or of their own making.

If, however, anyone finds themselves down the road, or presently, in a situation where the plan isn't providing growth and fish are stalling prior to the ultimate weight goal. Also where one has been diligent to cull bass and the only resolution is additional inputs ...
then I think what has one to lose?

The idea of harvesting > 6" BG is that their harvest results in a freeing of carrying capacity. Also these BG consume many of their own young below 3/4" in length. In a hatchery setting, it takes only a few breeding pairs to completely fill the carrying capacity with 2" BG in a couple of months. In the south a minimum of 3 crops of these can be produced. The point I am making is that the idea is to have a smaller biomass of breeders and a large biomass of YOY. BG can easily attain 4" in the first year where the biomass is below carrying capacity. LMB provide the cropping to keep the BOW below BG carrying capacity which stimulates additional breeding and crops of YOY BG.

Chunting's old clubs used this strategy along with LMB culling to grow > 10lb bass. So if all else is failing, it is very much worth giving it a try.

Last edited by jpsdad; 12/05/18 04:50 PM.

It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers


Joined: Jun 2015
Posts: 618
Likes: 73
Offline
Joined: Jun 2015
Posts: 618
Likes: 73
Originally Posted By: jpsdad
Originally Posted By: DrLuke
I am strictly going off memory here (from PB posts) but I've read about 1 to 3 ratio, regarding LMB length and the necessary gape size for larger prey fish. So the thinking is, a 12" LMB could handle up to a 4" BG. Add to that the thinking that, the LMB would expend less energy on chasing and eating ONE or TWO 4" BG than 4 or 5 two to three inchers.

So so how does the 100 to 1 mass size ratio correlate to the above?


No the mass ratio is about 15 to 1. A 4" BG provides roughly 6.67% of a 12" LMB's body weight. It is enough to sustain 12" LMB for four days and if 12" LMB can eat one every day for 30 days he'll gain >30% of his body weight shocked !



Here is spreadsheet where you can play with the mass ratio:


Do you have some data, or can you comment, on the conversion ratio of the 'raw BG' into net body mass for the LMB?


"Politics": derived from 'poly' meaning many, and 'tics' meaning 'blood sucking parasites'.
Joined: May 2018
Posts: 1,882
Likes: 278
J
jpsdad Online Content OP
OP Online Content
J
Joined: May 2018
Posts: 1,882
Likes: 278
Originally Posted By: DrLuke
Originally Posted By: jpsdad


No the mass ratio is about 15 to 1. A 4" BG provides roughly 6.67% of a 12" LMB's body weight. It is enough to sustain 12" LMB for four days and if 12" LMB can eat one every day for 30 days he'll gain >30% of his body weight shocked !


Do you have some data, or can you comment, on the conversion ratio of the 'raw BG' into net body mass for the LMB?


Assuming 5lbs forage annually for maintenance works out to 1.36% of body mass daily maintenance. So actually maybe 5 days maintenance. That available for growth is the excess above maintenance :

6.67% - 1.36% = 5.3%

The relative weight ingested for growth over 30 days:

1.053^30 - 1 = 4.7- 1 = 3.7 times the starting weight

Divide by conversion of 10 to 1 = .37 or 37% .... to be conservative, I stated > than 30% growth.

The estimate relies on the validity of maintenance and gain conversion factors and it neglects the rising maintenance as the fish grows through the 30 days.

>30% in one month is AWESOME but most pond-owners have LMB that surpass that growth early in the life of the BOW. Let's say you grow your initial stocker LMB from 2" to 2lbs in the first 12 months. The monthly growth must average 74%/month in order to achieve the weight. Most of the growth rate is frontloaded where the bigger the LMB gets, the slower its rate of growth. Even so, to achieve 2lbs in 12 months likely requires >30% monthly growth rate when the fish is 1lb.

Last edited by jpsdad; 12/05/18 04:47 PM.

It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers


Joined: May 2014
Posts: 3,861
Likes: 298
A
Offline
A
Joined: May 2014
Posts: 3,861
Likes: 298
Re checking the stomachs of LMB greater than 20 inches, it would be very stressful for me to kill such a fish. They are too hard to grow!

Last edited by anthropic; 12/05/18 05:28 PM.

7ac 2015 CNBG RES FHM 2016 TP FLMB 2017 NLMB GSH L 2018 TP & 70 HSB PK 2019 TP RBT 2020 TFS TP 25 HSB 250 F1,L,RBT -206 2021 TFS TP GSH L,-312 2022 GSH TP CR TFS RBT -234, 2023 BG TP TFS NLMB, -160




Joined: May 2018
Posts: 1,882
Likes: 278
J
jpsdad Online Content OP
OP Online Content
J
Joined: May 2018
Posts: 1,882
Likes: 278
Originally Posted By: anthropic
Re checking the stomachs of LMB greater than 20 inches, it would be very stressful for me to kill such a fish. They are too hard to grow!


No worries Frank. The request was for harvested fish only. Perhaps a candidate for this might be tubguy who has a goal of 5 - 6 lbs ultimate weight with lots of 2+ lbers. His plan involves harvesting fish when they reach 20 inches (5 lbs) to keep the cycle going. Plus he has many 3lb+ fish he currently needs to harvest. His BOW could provide a lot of useful data just working with the harvest he is planning.

Last edited by jpsdad; 12/05/18 05:56 PM.

It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers


Joined: Jun 2015
Posts: 618
Likes: 73
Offline
Joined: Jun 2015
Posts: 618
Likes: 73
Originally Posted By: jpsdad
Originally Posted By: DrLuke
Originally Posted By: jpsdad


No the mass ratio is about 15 to 1. A 4" BG provides roughly 6.67% of a 12" LMB's body weight. It is enough to sustain 12" LMB for four days and if 12" LMB can eat one every day for 30 days he'll gain >30% of his body weight shocked !


Do you have some data, or can you comment, on the conversion ratio of the 'raw BG' into net body mass for the LMB?


Assuming 5lbs forage annually for maintenance works out to 1.36% of body mass daily maintenance. So actually maybe 5 days maintenance. That available for growth is the excess above maintenance :

6.67% - 1.36% = 5.3%

The relative weight ingested for growth over 30 days:

1.053^30 - 1 = 4.7- 1 = 3.7 times the starting weight

Divide by conversion of 10 to 1 = .37 or 37% .... to be conservative, I stated > than 30% growth.

The estimate relies on the validity of maintenance and gain conversion factors and it neglects the rising maintenance as the fish grows through the 30 days.

>30% in one month is AWESOME but most pond-owners have LMB that surpass that growth early in the life of the BOW. Let's say you grow your initial stocker LMB from 2" to 2lbs in the first 12 months. The monthly growth must average 74%/month in order to achieve the weight. Most of the growth rate is frontloaded where the bigger the LMB gets, the slower its rate of growth. Even so, to achieve 2lbs in 12 months likely requires >30% monthly growth rate when the fish is 1lb.


Thanks for walking me through the math! You actually answered my question before I even asked it, I just didn't realize it! I love the depth of knowledge people bring to the forum. I also think this thread is extremely interesting, in that it potentially challenges (and perhaps updates) prior management strategy. I know, I'll wait and see what the data says, but pretty exciting concept!
I added LMB to my pond in Oct 2017 (as corrective stocking), and my personal management plan doesn't call for start of harvest yet. But when I do, I'll be happy to add some data.


"Politics": derived from 'poly' meaning many, and 'tics' meaning 'blood sucking parasites'.
Joined: Feb 2011
Posts: 5,284
Likes: 288
Moderator
Offline
Moderator
Joined: Feb 2011
Posts: 5,284
Likes: 288
Originally Posted By: Bill Cody
...So if when eating it takes one too long to get food swallowed, food can easily get stolen. It behooves predators to eat as quickly as possible which to me means eat the smallest yet largest items that can be swallowed quickly.

As a rule, the largest LMB(9#'+) in the pack I fed are the most aggresive, and the first to grab a handout. I've had them attack a 4-5" CNBG/GSF and swim away, and I've also seen the same LMB come back 2 more times and feed again. That's far rarer. 20+" LMB rarely hit a 8" CNBG here.

The biggest CNBG I've removed from a LMB here was 10.5". Probably an old CNBG that was slow moving. The LMB didn't survive the meal.

I've posted all this before, but over the last 4-5 years, I've really cut back on feedings in the upper part of our pond where most of the CNBG spawning beds are. These fish are fed once or twice a day for one second only, and dependent on the season. These fish primarily get a maintenance diet of 1/8" pellets and nothing more. I want them in that smaller LMB gape friendly range for as long as possible. More pellets per pound means more fish eat, and are more apt to spread the calories evenly. The feeder at our dam is targeting trophy sized CNBG (10"+) and only 9.5mm pellets are thrown, and are thrown multiple times a day. Short throws seem to keep smaller CNBG away from the open water frenzy. Both methods seem to work as intended.

So here's a question. What's the gape of this LMB? Is it 5.5" from extended lip to lip, or is it 4.75" from the protrusions on the roof palette to the lower lip? This LMB was 9#'s, and if measuring from the narrowest part of the mouth opening (4.75"), she would max out at about an 8-8.5" CNBG, which has an average height of 4" here. 10" CNBG average 6-6.25" height. Gape determines everything.






Attached Images
IMG_2879_lines.jpg IMG_2880_Lines.jpg
Last edited by FireIsHot; 12/05/18 07:05 PM. Reason: spelling

AL

Joined: May 2018
Posts: 1,882
Likes: 278
J
jpsdad Online Content OP
OP Online Content
J
Joined: May 2018
Posts: 1,882
Likes: 278
Originally Posted By: DrLuke

Thanks for walking me through the math! You actually answered my question before I even asked it, I just didn't realize it! I love the depth of knowledge people bring to the forum. I also think this thread is extremely interesting, in that it potentially challenges (and perhaps updates) prior management strategy. I know, I'll wait and see what the data says, but pretty exciting concept!
I added LMB to my pond in Oct 2017 (as corrective stocking), and my personal management plan doesn't call for start of harvest yet. But when I do, I'll be happy to add some data.


Most welcome Dr. Luke.

To be sure, I can't take credit for the concept of removing larger sizes of BG. Chunting's clubs were doing this decades ago and while this regional management method seems to have been widely known by the local private managers and their members, it also seems to have been a widely kept secret or now forgotten lore. It was Chunting's remarks that got me to asking the question and so I totally agree about how there is so much to learn here.

Thanks for offering to add to the data! As I compile it, I'll update in synopsis and also detailed form and share with all.

Last edited by jpsdad; 12/05/18 07:30 PM.

It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers


Joined: May 2018
Posts: 1,882
Likes: 278
J
jpsdad Online Content OP
OP Online Content
J
Joined: May 2018
Posts: 1,882
Likes: 278
Originally Posted By: FireIsHot


So here's a question. What's the gape of this LMB? Is it 5.5" from extended lip to lip, or is it 4.75" from the protrusions on the roof palette to the lower lip? This LMB was 9#'s, and if measuring from the narrowest part of the mouth opening (4.75"), she would max out at about an 8-8.5" CNBG, which has an average height of 4" here. 10" CNBG average 6-6.25" height. Gape determines everything.



I would lean toward to the 4.75" measurement or perhaps just in between. It might interest you to learn that the 100 to 1 mass ratio is fullfilled at 4.5" for a 8.5lb 24" LMB and at 4.7" for 9.78 lb 25" LMB. These are standard LMB and BG weights. In both cases, the length is between 1/6 and 1/5 the length of the LMB (.188).

A BG has spines in its dorsal fins and extends them rigidly as defense. This may also play a role.

Looking at the photograph got me to think about another relevant feature of the mouth that might contribute to the success of capture. Its that tounge. Its there for a purpose and I think that purpose is to push prey to rear of the mouth. It may be used in conjuction with the roof pads for constraining prey motion. What are your thoughts Al? Would the tounge affect the measurement of effective gape?

Last edited by jpsdad; 12/05/18 08:26 PM.

It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers


Joined: Oct 2014
Posts: 6,080
Likes: 1
Offline
Joined: Oct 2014
Posts: 6,080
Likes: 1
Originally Posted By: jpsdad
Originally Posted By: anthropic
Re checking the stomachs of LMB greater than 20 inches, it would be very stressful for me to kill such a fish. They are too hard to grow!


No worries Frank. The request was for harvested fish only. Perhaps a candidate for this might be tubguy who has a goal of 5 - 6 lbs ultimate weight with lots of 2+ lbers. His plan involves harvesting fish when they reach 20 inches (5 lbs) to keep the cycle going. Plus he has many 3lb+ fish he currently needs to harvest. His BOW could provide a lot of useful data just working with the harvest he is planning.


Our pond is only an avg. of .5 acre and we harvest all LMB over 15 inches. Biggest to date is 18.75 inches. If the stomach content data on these fish would be helpful, I will be happy to provide it. If the info from these LMB is useful, should I report the data back to this thread or are you going to start a dedicated thread to the activity?


[Linked Image]
Be Brave Enough to Suck at Something New!
Joined: Apr 2002
Posts: 15,110
Likes: 478
B
Moderator
Ambassador
Field Correspondent
Lunker
Offline
Moderator
Ambassador
Field Correspondent
Lunker
B
Joined: Apr 2002
Posts: 15,110
Likes: 478
This thread continues in the GREAT discussion territory. It is innovative and creative thinking by our members.


aka Pond Doctor & Dr. Perca Read Pond Boss Magazine -
America's Journal of Pond Management
Joined: May 2018
Posts: 1,882
Likes: 278
J
jpsdad Online Content OP
OP Online Content
J
Joined: May 2018
Posts: 1,882
Likes: 278
Originally Posted By: Bill D.

Our pond is only an avg. of .5 acre and we harvest all LMB over 15 inches. Biggest to date is 18.75 inches. If the stomach content data on these fish would be helpful, I will be happy to provide it. If the info from these LMB is useful, should I report the data back to this thread or are you going to start a dedicated thread to the activity?


Good question Bill. I think a new thread is in order just for keeping records. It would be best if contributors list all their data in a single post and just append as needed when they acquire new data. I will start one and post a link in this thread.

So here is another question. Do we just want to keep data on locale, LMB Length, LMB weight, Forage Lengths, BOW size? Other possible data might be BG harvest weights, etc. Whatever, we find, we'll most certainly ask more questions and the more detailed the data the more we will be able to glean from it. I'll just ask for the initial suggestions unless members weigh in on additional data.


It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers


Joined: Oct 2014
Posts: 6,080
Likes: 1
Offline
Joined: Oct 2014
Posts: 6,080
Likes: 1
My vote would be the more data the better without making it a huge task. First thing that came to my mind was is there a difference in forage size preference between Northern LMB, Florida LMB and F1 LMB.

Last edited by Bill D.; 12/05/18 08:15 PM.

[Linked Image]
Be Brave Enough to Suck at Something New!
Joined: May 2014
Posts: 3,861
Likes: 298
A
Offline
A
Joined: May 2014
Posts: 3,861
Likes: 298
Bob Lusk has said that gizzard shad are really important for growing giant LMB. He generally recommends them for people who focus on lunker bass.

Gizzards can get up to 2 lb, unlike threadfin shad which top out around six inches.

Last edited by anthropic; 12/05/18 10:38 PM.

7ac 2015 CNBG RES FHM 2016 TP FLMB 2017 NLMB GSH L 2018 TP & 70 HSB PK 2019 TP RBT 2020 TFS TP 25 HSB 250 F1,L,RBT -206 2021 TFS TP GSH L,-312 2022 GSH TP CR TFS RBT -234, 2023 BG TP TFS NLMB, -160




Joined: Jan 2006
Posts: 16,028
Likes: 274
D
Moderator
Lunker
Offline
Moderator
Lunker
D
Joined: Jan 2006
Posts: 16,028
Likes: 274
Coupla thoughts.

First, all impoundments(water holes with fish) are different.

Lusk sez that 99.5% of the eggs laid will never develop into mature(whatever that is) fish. They get eaten. And that's not a bad thing. And, the larger bluegills play an important role in cropping their own and bass offspring. I've watched male bass trying to protect a nest with fingerlings from BG and small bass predation multiple times. That's Mama Nature at work.

Due to growing and feeding seasons, this stuff is regional. In the South with a longer spawning, feeding and growing season, there are few parallels between water holes here and those further North. Heck, my North Texas ponds differ from Al Halls East Texas ponds. He gets more rains and I get more drawdowns from Mama Nature. And the drawdowns, as much as I hate them, make more forage available to predators.

In the warmer climates with the longer growing seasons, I think we are more likely to have oxygen crashes due to having too many fish. Been there, done that and have had to clean up the mess more than once.

In our area, only Bluegills spawn enough to feed bass and only bass can control bluegill spawning to prevent an O2 crash.

We all try for balanced ponds. Heck, without our intervention, that's generally about 15 minutes during the life of the pond. And culling and cannibalism are our tools.


It's not about the fish. It's about the pond. Take care of the pond and the fish will be fine. PB subscriber since before it was in color.

Without a sense of urgency, Nothing ever gets done.

Boy, if I say "sic em", you'd better look for something to bite. Sam Shelley Rancher and Farmer Muleshoe Texas 1892-1985 RIP
Joined: May 2018
Posts: 1,882
Likes: 278
J
jpsdad Online Content OP
OP Online Content
J
Joined: May 2018
Posts: 1,882
Likes: 278
Bill, I'll add the flag of LMB strain.

Thanks to everyone who commented. I'll post a separate thread for data and reference in this post later today.


It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers


Joined: Feb 2011
Posts: 5,284
Likes: 288
Moderator
Offline
Moderator
Joined: Feb 2011
Posts: 5,284
Likes: 288
Originally Posted By: jpsdad
...Looking at the photograph got me to think about another relevant feature of the mouth that might contribute to the success of capture. Its that tounge. Its there for a purpose and I think that purpose is to push prey to rear of the mouth. It may be used in conjuction with the roof pads for constraining prey motion. What are your thoughts Al? Would the tounge affect the measurement of effective gape?


I'm not sure, but the abrasions on the palette make me think it's part of the process by either holding or helping swallow the forage.

4.75" is the more conservative number, and what I would go by here. Having said that, LMB are opportunistic feeders, so their diet is probably determined primarily by availability as much as anything.

EDIT: I didn't take the tongue into account for 2 reasons. One, the vertical gape is the most common and easily determined choice for forage sizing, and two, I was unable to manipulate the LMB's mouth into a true flared opening, so any numbers I had would get would probably be sketchy at best.

Sometimes LMB make poor choices based on that availability.


Attached Images
IMG_4932 2_800.jpg
Last edited by FireIsHot; 12/06/18 08:39 AM.

AL

Joined: Sep 2014
Posts: 3,668
Likes: 57
T
Offline
T
Joined: Sep 2014
Posts: 3,668
Likes: 57
jpsdad, smaller biomass of breeders and larger biomass of yoy bg. I have been working on that since the beginning. Producing lots of bg, that is! I will never forget the time when Todd Overton came to the pond and made recommendations for me to build some brush piles along the shoreline for the cnbg fry to improve their survival where I would produce more 2 to 3" bg. I lacked vegetation so the brush piles gave the bg fry a place to hide. We also stocked an additional 25 lbs of FHM's to reduce the pressure on the bg fry. Later on, after doing the brush piles, I had a boom in 3" cnbg. Hundreds and hundreds of them. The brush piles really worked. I had lots cover around the pond water but not so much against the shoreline until I followed Todd's Recommendations.


The information I have seen lead me to believe I needed to keep the larger sized >7" cnbg for breeders. More >7", and they produced the most fry. Just the opposite from what I have read here in this thread. If I am understanding it? I am not fussing here, just thinking out loud. I maybe confused as I am not the sharpest pencil in the box when it comes to growing trophy lmb.

And Al, I have given much thought about reducing the feeding of the smaller cnbg and have reduced the amount of feed I once fed. Wanting to reduce growth rates on my bg along with reducing nutrients into the pond. You could have shared the comments on feeding less around the spawning areas a few yrs ago and saved me some bucks I spent on feed. smile Just messen with ya! And thanks for your input, it reinforced my feeding thoughts and opened my eyes on mouth gape for providing the right sized forage to my lmb.

jpsdad, thanks for bringing this all up! Good info, keeps me thinking on how to get my lmb larger faster.

Last edited by TGW1; 12/06/18 09:26 AM.

Do not judge me by the politicians in my City, State or Federal Government.


Tracy
Joined: May 2014
Posts: 3,861
Likes: 298
A
Offline
A
Joined: May 2014
Posts: 3,861
Likes: 298
I'm wondering if the best feeding strategy might be to use larger pellets that big CNBG can eat but not so much the little guys. Sure, the pellets will soften and little guys will get some, but less than they would small pellets. That way the big breeders will do well, but the smaller fish would stay bite size longer.

Last edited by anthropic; 12/06/18 11:59 AM.

7ac 2015 CNBG RES FHM 2016 TP FLMB 2017 NLMB GSH L 2018 TP & 70 HSB PK 2019 TP RBT 2020 TFS TP 25 HSB 250 F1,L,RBT -206 2021 TFS TP GSH L,-312 2022 GSH TP CR TFS RBT -234, 2023 BG TP TFS NLMB, -160




Joined: Feb 2011
Posts: 5,284
Likes: 288
Moderator
Offline
Moderator
Joined: Feb 2011
Posts: 5,284
Likes: 288
Originally Posted By: TGW1
...The information I have seen lead me to believe I needed to keep the larger sized >7" cnbg for breeders. More >7", and they produced the most fry. Just the opposite from what I have read here in this thread. If I am understanding it? I am not fussing here, just thinking out loud. I maybe confused as I am not the sharpest pencil in the box when it comes to growing trophy lmb.


Tracy you're correct, you should keep your larger CNBG for spawners. We stock them at 8" primarily because we have an older pond, and I feel like that #'s safe for the majority of them. I just like my smaller CNBG to slow roll through puberty.


AL

Joined: Mar 2005
Posts: 21,475
Likes: 264
E
Moderator
Hall of Fame 2014
Lunker
Offline
Moderator
Hall of Fame 2014
Lunker
E
Joined: Mar 2005
Posts: 21,475
Likes: 264
Some interesting parts of the study IMO.

Table 4
Literature review of study piscivore gape-limits and maximum ingested prey size estimates.

Predator taxon Prey taxon Study Type Estimate Type % Body Length Reference


Largemouth Bass All Prey Field survey Max. model 30–35% Goldstein [58]

Largemouth Bass All Prey Field survey 90th %tile value 33% Pierce, Sexton [57]

Largemouth Bass All Prey Field survey Max. value 71% Pierce, Sexton [57]

Largemouth Bass Bluegill Gape-limit Max. model 34–35% Lawrence [56]

Largemouth Bass Gizzard Shad Gape-limit Max. model 34–49% Lawrence [56]

Largemouth Bass Largemouth Bass Gape-limit Max. model 44–58% Lawrence [56]c


Early optimal foraging (or diet) theory predicted that predators optimally forage by selecting prey that maximizes energy gain while minimizing handling time [2, 10, 17–19]. Optimal foraging theory, therefore, predicts that IPmax and IP50 should increase linearly with predator size [10] and is limited only by gape (i.e., gape-limit; [21]). While this has served as a foundation for gape-limitation research, studies over the last quarter century have shown that piscivore predation does not follow this pattern as prey mobility may influence both encounter rate and capture efficiencies [21, 22, 48, 52–54]. Furthermore, energetically favorable large prey fishes are often relatively scarce in ecosystems [48]. While piscivores become more effective predators with size due to increased swimming speed, burst capabilities, and visual acuity, prey fishes similarly become more effective at avoiding predation with size [2, 48, 55]. Our findings support these developments in optimal foraging theory that suggest foraging success on mobile prey is not simply a function of gape limitation and handling time, but also of search time, encounter rate, opportunity, and prey behavior [52, 53].


A common approach to estimate IPmax is the gape-limit method (Fig 2, Line c; Table 4; e.g., [56]). However, this method assumes predator mouth size is the only determinant of prey size and does not account for prey availability, prey behavior, handling time, capture success, or competition, which often results in overestimated IPmax for larger individuals.

We acknowledge that our results have limitations (e.g., low sample sizes for crappie, smallmouth bass, and rock bass; northern pike observations from only two lakes; and a lack of information on prey fish community size structure available in the ecosystem) and, therefore, stress that these are “realized” prey lengths, not “preferred” prey lengths.

Furthermore, while it has been shown that the size distribution of prey fishes available in the environment do not reflect those observed in the diet [50], we recommend future analyses compare the distribution of prey total lengths found in diets to the distribution of length observed in the ecosystem. Despite potential shortcomings, examining predator-prey total length relationships for a variety of taxa across multiple lakes, as in our study, provides an empirical basis for assessing how predation can structure or influence populations, communities, and aquatic ecosystems.

Last edited by ewest; 12/07/18 01:13 PM.















Joined: Sep 2003
Posts: 13,689
Likes: 281
Moderator
Ambassador
Field Correspondent
Hall of Fame 2014
Lunker
Online Content
Moderator
Ambassador
Field Correspondent
Hall of Fame 2014
Lunker
Joined: Sep 2003
Posts: 13,689
Likes: 281
" I just like my smaller CNBG to slow roll through puberty."

Freak.


Excerpt from Robert Crais' "The Monkey's Raincoat:"
"She took another microscopic bite of her sandwich, then pushed it away. Maybe she absorbed nutrients from her surroundings."

Joined: May 2018
Posts: 1,882
Likes: 278
J
jpsdad Online Content OP
OP Online Content
J
Joined: May 2018
Posts: 1,882
Likes: 278
Eric,

You didn't expand on why you find that interesting. I did notice that you highlighted the predicted maximum lengths reported by various author based on their measurements of gape. The authors of this paper never objected to these findings of "estimated maximum lengths" as these lengths are approached, thought not realized, in the evidence they evaluated. In the practical sense, the "realized prey lengths" are just what the predators were doing going about their daily lives of being a predator. The realized prey lengths were remarkably similar across a broad number of predators and for individual predators across a broad range of predator sizes.

What I found interesting is that the smaller prey dominates the samples and I took it to mean that the predators were gaining benefit from them. This could be important. First because a BOW can produce a greater weight of smaller fish annually as forage, but also for other management decisions. For example they mentioned in the paper how a DNR was using their findings to determine the optimum size to stock Walleye in waters with bass predators.

Tracy,

To truly understand what effects >6" BG harvest may have on a BOW, we would need a situation where a BOW had plentiful >6" BG and the owner has been keeping a detailed ongoing record of LMB catches and weights. A good candidate would be a BOW with a continuing decline of > 20" LMB RWs. If harvesting >6" BG were to increase forage availability to 20" LMB then RWs might be expected to increase. To be sure, it isn't a trickle down effect, rather, it is a trickle up effect where the largest predators get what survives their smaller neighbors. An increase in all LMB RW's would be significant supporting evidence that more forage was provided. If the largest LMB are benefited by removing >6" LMB then one can only conclude that more plentiful <6" forage was a greater benefit to them. If however, the >20" LMB condition worsens significantly, I would have to wonder if the harvest of >6" BG took food away from them.

***Bump***

Tracy one other means of determining optimum adult BG biomass has occurred to me. From the perspective of an experiment ... one approach might be to stock total weight of BG adults with a specific weight of LMB (say 4 lb LMB at rate of 100 _lbs/acre). Allow a growing season from May to November. The optimum Adult BG Biomass might indicate the carryover you need to optimize forage production.

Last edited by jpsdad; 12/07/18 03:50 PM.

It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers


Joined: Mar 2005
Posts: 21,475
Likes: 264
E
Moderator
Hall of Fame 2014
Lunker
Offline
Moderator
Hall of Fame 2014
Lunker
E
Joined: Mar 2005
Posts: 21,475
Likes: 264
It takes reading a few studies and books to learn the terms used and how they are used . I went back and highlighted text that relates to this thread.

Much of this in common terms is common sense. The above text has inconsistencies in my opinion. I think using basic basic energetics theory is better. The fish will eat what provides the most energy overall. Not necessarily the biggest fish it can swallow. Fish instinctively will go for the prey that will provide the most benefit after deducting the energy cost to catch and process. That is on an individual basis. If a few fish are better at catching big prey and can do so at low cost they will have the best chance of becoming the trophies.

Last edited by ewest; 12/07/18 01:22 PM.















Joined: May 2018
Posts: 1,882
Likes: 278
J
jpsdad Online Content OP
OP Online Content
J
Joined: May 2018
Posts: 1,882
Likes: 278
Originally Posted By: ewest
I think using basic basic energetics theory is better. The fish will eat what provides the most energy overall. Not necessarily the biggest fish it can swallow.. .


This makes a whole lot of sense to me. Even so, to be true ... the distributions of forage lengths observed reflect the distribution of sizes that were providing the "most energy overall" for the predators sampled.


It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers


Joined: Mar 2005
Posts: 21,475
Likes: 264
E
Moderator
Hall of Fame 2014
Lunker
Offline
Moderator
Hall of Fame 2014
Lunker
E
Joined: Mar 2005
Posts: 21,475
Likes: 264
Yes all fish are not the same - they adapt or die. Some will be better at catching many small prey and others will eat fewer but bigger meals and still others will do some of both. Your selection of goals and how to achieve them have to account for many variables some of which are difficult to control/plan for. The most important one (one often noted in studies as problematical) for most waters is lack of food.

Here is one point I noted from the text:

"We acknowledge that our results have limitations (e.g., low sample sizes for crappie, smallmouth bass, and rock bass; northern pike observations from only two lakes; and a lack of information on prey fish community size structure available in the ecosystem) and, therefore, stress that these are “realized” prey lengths, not “preferred” prey lengths."

That is a big if to be missing on.

It could be that those systems were out of balance (which is common) and that there were not many big BG to eat.

Last edited by ewest; 12/07/18 04:46 PM.















Joined: May 2018
Posts: 1,882
Likes: 278
J
jpsdad Online Content OP
OP Online Content
J
Joined: May 2018
Posts: 1,882
Likes: 278
Originally Posted By: ewest


Here is one point I noted from the text:

"We acknowledge that our results have limitations (e.g., low sample sizes for crappie, smallmouth bass, and rock bass; northern pike observations from only two lakes; and a lack of information on prey fish community size structure available in the ecosystem) and, therefore, stress that these are &#147;realized&#148; prey lengths, not &#147;preferred&#148; prey lengths."

That is a big if to be missing on.

It could be that those systems were out of balance (which is common) and that there were not many big BG to eat.


This is certainly an unknown. For LMB samples, however, the size of BG that fit the gape are not that large. Almost all of the LMB predators were less than 16". One has to wonder why the 10" LMB weren't primarily feeding on 3" BG if the 15" LMB were consuming primarily ~3". If 3" LMB are abundant enough to feed 15" LMB, what explanation remains as to why they weren't also abundant for the 10" LMB? If we argue its merely a reflection of abundance (or lack of)... more complicated theories must be constructed to justify why the abundance of 1/4 to 1/3 length prey were not predominately consumed by the smaller predators. Even so, it is unknown and I do think it is far less about "preference" and much more about "opportunity".


It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers


Joined: Jan 2006
Posts: 16,028
Likes: 274
D
Moderator
Lunker
Offline
Moderator
Lunker
D
Joined: Jan 2006
Posts: 16,028
Likes: 274
Agree with opportunity. Neither predator nor prey have the ability to reason but are more reactive. But, that's not to say that they can't learn.


It's not about the fish. It's about the pond. Take care of the pond and the fish will be fine. PB subscriber since before it was in color.

Without a sense of urgency, Nothing ever gets done.

Boy, if I say "sic em", you'd better look for something to bite. Sam Shelley Rancher and Farmer Muleshoe Texas 1892-1985 RIP
Joined: Sep 2014
Posts: 3,668
Likes: 57
T
Offline
T
Joined: Sep 2014
Posts: 3,668
Likes: 57
I would like to add information to your new thread but for now the Florida lmb in the 17 to 17 1/2" are in the 120 to 124% RW range. So I have no plans on harvesting those fish at this time. If I was to harvest one, it would be most likely be due to poor condition, like blind in one eye or something else. And that might skew the results, I would think. However I am pretty sure, one day in the future I will be removing some for harvest due to RW of the fish. I hope I don't have to harvest larger sized lmb but if everything goes as planned then most likely I will and I would be happy to report what I see in stomach contents.


Do not judge me by the politicians in my City, State or Federal Government.


Tracy
Joined: Oct 2014
Posts: 6,080
Likes: 1
Offline
Joined: Oct 2014
Posts: 6,080
Likes: 1
Originally Posted By: Dave Davidson1
Agree with opportunity. Neither predator nor prey have the ability to reason but are more reactive. ....


Yes! This makes a lot of sense to me. It seems intuitive to me that there is a minimum size BG must attain to be of interest to LMB and trigger an attack (reactive). For purpose of discussion, assume that is 3 inches for larger LMB. Arguably, there are significantly more 3 inch BG in a typical pond's population than each larger size class, which implies that there is an increased opportunity for LMB to feed on 3 inch BG than larger. I wonder if the stomach content of LMB in pond's where the BG are fed pellets, and BG grow more quickly, have a corresponding increase in size of stomach contents as the population density distribution of the size classes of BG is skewed toward larger sizes.

Just thinking out loud............

Last edited by Bill D.; 12/08/18 08:11 AM.

[Linked Image]
Be Brave Enough to Suck at Something New!
Joined: Sep 2014
Posts: 3,668
Likes: 57
T
Offline
T
Joined: Sep 2014
Posts: 3,668
Likes: 57
Here is a thought I had. In my pond, the lmb in the size range requested, are usually caught off structure in the deeper water. The smaller sized lmb are caught nearer the shore. That is two different types of locations. An exception would be during the spawn where I have caught a few larger lmb in shallower water or near a feeder that is throwing into deep water. And when I bg fish or feed the bg I will see or catch the smaller bg in the shallower water and not so much in the deeper water. The larger lmb that hang in or near deeper water may be feeding on larger bg. I base this on me catching my largest bg in that deeper water or nearer to the deeper water. I know larger lmb will move up to feed but I also know they may not move up and will feed in the deeper water if there is a place for them to ambush their prey. For me, deeper water structure = larger lmb and larger bg. Pond designs can or might make a difference in what sized prey a lmb might use with keeping in mind mouth gape size.


They ponds mentioned were not described and I would think a pond where there is little structure and or cover could influence the size and numbers of bg. The bg were never allowed to grow larger because of harvest and there was no place for them to hide from the predators. Leaving mostly 3 to 4" bg.


I need to measure the depth of my 6" bg because to me a 6" bg is not all that big and could easly be swallowed by a 4 to 5 lb lmb.


Do not judge me by the politicians in my City, State or Federal Government.


Tracy
Joined: May 2018
Posts: 1,882
Likes: 278
J
jpsdad Online Content OP
OP Online Content
J
Joined: May 2018
Posts: 1,882
Likes: 278
There are so many great intuitions in these last comments it will take some effort to respond to all of them. I will respond to those which most moved me in just one post as time is provided me.

Originally Posted By: Dave Davidson1
Agree with opportunity. Neither predator nor prey have the ability to reason but are more reactive. But, that's not to say that they can't learn.


How does the star quarterback place that throw right where his receiver can catch it? Why is a veteran quarterback better than a rookie at doing it? The geodesic a pass follows in terms of physics is an elegant solution of least time. But the quarterback cannot rely on this solution to assist with his throw. His reactions must be made quickly and the "computations" his brain makes to drive these reactions are performed below the level of cognition. He might say his gut drives the decision making and tells him whether a pass to a particular player is "too risky" or a "good opportunity". He might also say his arm just "knows" how hard to throw the ball and at what angle to throw it.

From my perspective, I think an opportunity is an action that has high likelihood of success and provides a benefit or gain. A dis-opportunity is an action associated with disproportionate risk or a likelihood of loss. Like Dave, I think LMB can learn below the level of cognition and doing so allows them react to situations that are opportunities and restrain from acting to situations that are less opportunistic or carry unnecessary risk.

Originally Posted By: Bill D
For purpose of discussion, assume that is 3 inches for larger LMB. Arguably, there are significantly more 3 inch BG in a typical pond's population than each larger size class, which implies that there is an increased opportunity for LMB to feed on 3 inch BG than larger. I wonder if the stomach content of LMB in pond's where the BG are fed pellets, and BG grow more quickly, have a corresponding increase in size of stomach contents as the population density distribution of the size classes of BG is skewed toward larger sizes.


This is the $64,000 question. Will LMB adapt to eating larger prey when they are forced to by necessity? I would love to "KNOW" the answer to this.

But to begin, let me say that I think the results reflected in the paper on LMB in the 10" and smaller class is evidence supporting the proposition that LMB have a reactive pattern with regard to prey length. It is worth asking if this pattern reflects maximized opportunity and minimized risk with regard the natural and instinctual capability of LMB to capture prey and BG to evade predation. If so, then adapting to the new prey size structure might be problematic. If the LMB "realized" prey distribution remains the same then one might wonder whether feeding BG could take food from them. But I think it more complex than this ... feeding improves condition of breeding BG and stimulates spawning ... feed excrement fertilizes at the bottom of the food chain making food available for BG offspring. In the short term, there may be observable improvement due to increased YOY production but long term, however, it may be more like pushing on a string. Whatever the case, there will be annual mortality of BG due to old age and this will free space for YOY production.

I am beginning to wonder if YOY provide the bulk of the food for the entire population of LMB. If so, then one doesn't need a large surviving population at the onset of annual spawning. Think of it like a corn field. You need seed for a new crop but you don't need the entire crop from last year for seed. The most BG YOY in terms of weight will be produced when parents occupy a smaller proportion of BG biomass and predators crop the YOY heavily. YOY cropping is necessary for maximum yield because it keeps BG biomass below carrying capacity allowing secondary trophic organisms to flourish. The cropping continually provides room to grow and stimulates additional spawning .

In the case of tilapia, 20 lbs per acre results in significant YOY production. Some similar but different weight of BG brooders provides a similar optimum production, whatever it is, though it is probably a function of several variables to include primary production capacity (fertility), BG brooder biomass, BG brooder sex ratio, LMB biomass and LMB size distribution.

If LMB can get all the nutrition they need from <1 year BG and if a BOW carries a large proportion of its BG biomass in >1 year BG, then a small proportion of BG carrying capacity would be available for the production of BG YOY. This would mean that YOY BG crops are diminished in BOWs carrying a large weight of >1 year BG. I would argue that this is why new ponds are so productive. The reality is that BOWs get more fertile with age and this seems to fly against the early production. And so I argue that newly stocked ponds are more efficient at producing new YOY crops because the parental BG standing weights are lower. This means that BOW with lower fertility could produce greater production of LMB than a BOW of greater fertility .... provided .... the parental BG standing weights of the less fertile BOW allow for greater production of BG YOY.

With regard to feeding, it may be more advantageous to feed at the bottom of the food chain. First by fertilization and optimizing the chemical composition of the BOW. Where food is added, it may be more advantageous to provide feed to the base of food chain directly to shredders and detrivores that will serve as food for BG YOY.

Originally Posted By: TGW1
Here is a thought I had. In my pond, the lmb in the size range requested, are usually caught off structure in the deeper water. The smaller sized lmb are caught nearer the shore. That is two different types of locations. An exception would be during the spawn where I have caught a few larger lmb in shallower water or near a feeder that is throwing into deep water. And when I bg fish or feed the bg I will see or catch the smaller bg in the shallower water and not so much in the deeper water. The larger lmb that hang in or near deeper water may be feeding on larger bg. I base this on me catching my largest bg in that deeper water or nearer to the deeper water. I know larger lmb will move up to feed but I also know they may not move up and will feed in the deeper water if there is a place for them to ambush their prey. For me, deeper water structure = larger lmb and larger bg. Pond designs can or might make a difference in what sized prey a lmb might use with keeping in mind mouth gape size.


Water depth is a spatial environment variable that I think is important to a fish's behavior to seek security. Depth is a type of cover that provides protection from terrestrial and avian predators. The deepest water with oxygen provides the most secure place to rest, recuperate, and digest their meals" This habitat belongs primarily to the largest fish. I think it could be argued that the large BG are there because the large LMB do not present as great a risk for them as other predators. This is not to say the large LMB cannot or will not eat them only that the probability favors the larger LMB taking action on smaller prey.

It could be that LMB are highly successful at capturing prey in the 1/6 to 1/4 length range and that failure risks associated with 1/4 to 1/3 length prey tend to prevent LMB from taking as frequent action.

Last edited by jpsdad; 12/08/18 12:52 PM.

It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers


Joined: Mar 2005
Posts: 21,475
Likes: 264
E
Moderator
Hall of Fame 2014
Lunker
Offline
Moderator
Hall of Fame 2014
Lunker
E
Joined: Mar 2005
Posts: 21,475
Likes: 264
It depends on so many factors - it is a very dynamic system with potential trophic cascades.

Fully adult (older than 1 year depending on location)BG produce many more offspring than first spawning BG (1 year) and the males are much better at keeping them alive while nesting. Small differences like that cam make a big difference in year class size and thus population dynamics. Another example is hiding places for yoy BG ( xmas trees or plants near spawning grounds). Even increasing survival rates 1 to 2% for 90 days makes a large difference.
















Joined: May 2018
Posts: 1,882
Likes: 278
J
jpsdad Online Content OP
OP Online Content
J
Joined: May 2018
Posts: 1,882
Likes: 278
Al,

Is the photograph you posted of the LMB and tilapia is one of your LMB? If so, did you happen to get length measurements of them? I've estimated the tilapia to be 45% the length of the LMB.

Also, I notice that the tilapia is lying horizontal relative to the LMB and wonder if effective gape should be measured from the width of the LMB's mouth. This would make sense if laterally compressed prey are generally swallowed in this horizontal position.


Last edited by jpsdad; 12/08/18 01:33 PM.

It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers


Joined: Feb 2011
Posts: 5,284
Likes: 288
Moderator
Offline
Moderator
Joined: Feb 2011
Posts: 5,284
Likes: 288
Yes, I waded out and pulled them out of a brush pile a couple of weeks ago. No numbers on either fish, as I threw them on the bank with the rest of the dead tilapia. The first freeze hit us hard, and I'm sure that the tilapia was near death, and offered little or no resistance. No way I can see a tilapia that big not escaping that LMB. Rapid freezes can really dump a lot of tilapia into the food mix, and there were no tilapia floating less than 10" long.

Not sure about the gape. The tilapia was actually at about a 45 degree angle, and is a little taller than the pics shows. If the LMB was in the process of repositioning the tilapia to a horizontal position, I wouldn't be the least bit surprised.


AL

Joined: May 2014
Posts: 3,861
Likes: 298
A
Offline
A
Joined: May 2014
Posts: 3,861
Likes: 298
Originally Posted By: ewest
Yes all fish are not the same - they adapt or die. Some will be better at catching many small prey and others will eat fewer but bigger meals and still others will do some of both.


Eric, I remember one of the plump LMB from the electrosurvey had a tiny, maybe 1 to 1.5 inch fish in the back of its throat. Could be simple random event, but we saw hundreds & hundreds of similar size YOY (too small to identify) shocked up from many weedbeds.

Perhaps some LMB learned to take advantage of superabundant prey, even though tiny, at least for while the abundance lasted.

Wonder if this is why minuscule lures sometimes catch giant bass? Most of my 9 lb plus LMB came on a 4 inch jigworm.

Last edited by anthropic; 12/08/18 08:07 PM.

7ac 2015 CNBG RES FHM 2016 TP FLMB 2017 NLMB GSH L 2018 TP & 70 HSB PK 2019 TP RBT 2020 TFS TP 25 HSB 250 F1,L,RBT -206 2021 TFS TP GSH L,-312 2022 GSH TP CR TFS RBT -234, 2023 BG TP TFS NLMB, -160




Joined: May 2018
Posts: 1,882
Likes: 278
J
jpsdad Online Content OP
OP Online Content
J
Joined: May 2018
Posts: 1,882
Likes: 278
I referenced a link to a Swingle paper in my post above regarding BG spawns and the conditions favorable to successful spawns. Notwithstanding the obvious advantages of BG size, BG condition is a very important factor for a successful spawn. The ideal circumstance is where BG spawn at regular intervals throughout the Summer months. This isn't always the case as Swingle observed below:


Originally Posted By: Swingle
For instance, during the same year within a 5-mile radius from Auburn, bluegills began to spawn in one pond in April and were observed spawning again during May, June, July, August and September; in another pond they spawned in May and again in September; in another the first spawning occurred in September.


Al's targeting of breeding size BG for feeding seems to me a good strategy for this purpose. Even so, survival of YOY to the size to benefit > 16" LMB (>2") must also be considered. Ideally, there must be sufficient weight and number of breeders to continually spawn all Summer, but not so many that they reduce the number of YOY BG surviving to 2". To this end, removal of small LMB and BG of breeding size that constitute an unneeded surplus of breeders should contribute to maximizing production of >2" YOY BG.

Last edited by jpsdad; 12/09/18 08:46 AM.

It isn't what we don't know that gives us trouble, it's what we know that ain't so - Will Rogers


Joined: Jan 2006
Posts: 16,028
Likes: 274
D
Moderator
Lunker
Offline
Moderator
Lunker
D
Joined: Jan 2006
Posts: 16,028
Likes: 274
I never cull BG. They are either groceries or predators of small bass.


It's not about the fish. It's about the pond. Take care of the pond and the fish will be fine. PB subscriber since before it was in color.

Without a sense of urgency, Nothing ever gets done.

Boy, if I say "sic em", you'd better look for something to bite. Sam Shelley Rancher and Farmer Muleshoe Texas 1892-1985 RIP
Page 1 of 3 1 2 3

Link Copied to Clipboard
Today's Birthdays
Bob Lusk, GaryK, GrizzFan, PhotographerDave
Recent Posts
Working on a .5acre disaster, I mean pond.
by Sunil - 03/28/24 05:33 PM
Relative weight charts in Excel ? Calculations?
by jpsdad - 03/28/24 04:51 PM
1 year after stocking question
by esshup - 03/28/24 04:48 PM
Fungus infection on fish
by BillyE - 03/28/24 04:35 PM
Yellow Perch Spawn 2024
by H20fwler - 03/28/24 04:29 PM
Alum vs Bentonite/Lathanum for Phosphorus Removal?
by FishinRod - 03/28/24 04:23 PM
New 2 acre pond stocking plan
by LANGSTER - 03/28/24 03:49 PM
Happy Birthday Bob Lusk!!
by ewest - 03/28/24 03:37 PM
Paper-shell crayfish and Japanese snails
by esshup - 03/28/24 10:39 AM
Brooder Shiners and Fry, What to do??
by Freg - 03/28/24 09:42 AM
Dewatering bags seeded to form berms?
by Justin W - 03/28/24 08:19 AM
Reducing fish biomass
by FishinRod - 03/28/24 08:18 AM
Newly Uploaded Images
Eagles Over The Pond Yesterday
Eagles Over The Pond Yesterday
by Tbar, December 10
Deer at Theo's 2023
Deer at Theo's 2023
by Theo Gallus, November 13
Minnow identification
Minnow identification
by Mike Troyer, October 6
Sharing the Food
Sharing the Food
by FishinRod, September 9
Nice BGxRES
Nice BGxRES
by Theo Gallus, July 28
Snake Identification
Snake Identification
by Rangersedge, July 12

� 2014 POND BOSS INC. all rights reserved USA and Worldwide

Powered by UBB.threads™ PHP Forum Software 7.7.5