Pond Boss
Posted By: Lukkyseven Mouth Gape of HSB - 04/15/14 01:45 PM
Is there any information on this? I'm looking and I can't find anything. I'm curious what the max gape of the mouth is based on the length of the fish.
Posted By: esshup Re: Mouth Gape of HSB - 04/15/14 02:11 PM
It's not anywhere near the size of LMB.

I know it's not the same fish but we would catch Stripers in Raccoon Reservoir on slow trolled 6"-7" BG. IIRC we didn't catch one less than 12# on BG that size.
Posted By: Lukkyseven Re: Mouth Gape of HSB - 04/15/14 02:23 PM
I'm curious for a few reasons, but I'd like to compare it to a SMB.

That's a big HSB though.
Posted By: Bill Cody Re: Mouth Gape of HSB - 04/15/14 03:33 PM
I'm not sure the mouth gape of HSB is published in the literature. ewest may be able to help us with this info in the literature. We have enough members here that we could do a data accumulation here on the forum for mouth gape of various sizes of HSB. I think the gape of HSB is smaller than that for SMB. As I recall the mouth gape of SMB is not "all that" smaller than for the same length of LMB. It would be a good idea if we compiled this information in the Archives for HSB, SMB and LMB. How about you doing some fishing and measuring to help us???? Please?

For those with ponds, lets go out and catch a fish and measure the fish's total length and the width across its full open mouth. Do not try to stretch the moth open to get extra width. Just hold the mouth open and measure across the opening. When we have numerous measurements this thread can go into the Archives about HSB information. Duplicate measurements are good and give us an idea of the natural variability. Thanks for fishing, measuring and contributing.

Here is my contribution for this project:
HSB Gape Information
Total length then Gape Width.
5.5" gape 0.59" (15mm)
9.75" gape 0.94" (24mm)
13.5" gape 1.1" (28mm)
19.0" gape 1.73" (44mm)
22.0" gape 2.1" (55mm)

Here are some data that I have for SMBass.
Total Lgn Gape Width
5.5" gape 0.71" (18mm)
9.5" gape 1.1" (28mm)
13.5" gape 1.57" (40mm)
17.0" gape 2.3" (58mm)

Here are some of my data for LMBass
Lgn Gape Width

5.5" Gape 0.83" (21mm)
9.5" gape 1.5" (39mm)
12.75" gape 2.0" (51mm)
17.0" gape 3.9" (100mm)
Posted By: Lukkyseven Re: Mouth Gape of HSB - 04/15/14 03:55 PM
I will gladly contribute once I catch a few. Let me ask my next question though (to clarify for myself).

Is the distance across the same as the top to bottom measurement? Would that even matter?
Posted By: CJBS2003 Re: Mouth Gape of HSB - 04/15/14 04:16 PM
It is different and it would matter, exactly how much I don't know. HSB are definitely the most gape restricted of the "bass" though. Since, we're at it, how about walleye gape since it seems to be a more and more commonly stocked predator into ponds these days... Bill, you happen to have that info handy as well? I know, CC have also been researched on mouth gape. I think Theo Gallus did a lot of work on that. I think crappies have a bigger gape than HSB do. I sure know a 15" crappie sure has a giant mouth! I honestly think a GSF has a bigger mouth than a HSB of the same size...
Posted By: DNickolaus Re: Mouth Gape of HSB - 04/15/14 04:21 PM
Great start to a nice research project!
I took the liberty of dividing gape by length and found that your very small samples are quite constant within a species and definitely show a trend.

HSB avg gape/length=0.094
SMB avg gape/length=0.124
LMB avg gape/length=0.174

So, HSB may be roughly half the gape width per body length as LMB.

Furthermore, I ran across the paper below which has info from Ohio research.

You can add two points for HSB: 22/220mm and 32/335mm.
Those yield gape/length=0.100 and 0.096. (min for smaller class cited as 190mm elsewhere in paper) The published data are in line with Bill's data.

Transactions of the American Fisheries Society, Vol. 127, No. 1, 1998, pp. 84-94.
http://kb.osu.edu/dspace/bitstream/handl....pdf?sequence=1
we estimated the largest prey that predators could consume by comparing gizzard shad body depth to hybrid striped bass mouth width. Hybrid striped bass efficiently consumed prey that were at their morphological limits of consumption. For hybrid striped bass shorter than 250 mm, the largest potential prey size was 80 mm (body depth = 22 mm), whereas for hybrid striped bass of 310-360 mm, the largest potential prey size was 120 mm (body depth = 32 mm). Regressing capture efficiency against the proportion of the maximum gape for each prey, we found no relationship for either predator size (linear regression, F = 0.07, df = 1, 8; P = 0.80 for large hybrid striped bass; F = 0.30, df = 1, 12; P = 0.60 for small hybrid striped bass). Consequently, hybrid striped bass in the laboratory can consume prey whose limiting dimension equals their maximum gape without reducing capture efficiency.
Posted By: Sunil Re: Mouth Gape of HSB - 04/15/14 05:58 PM
In general, the SMB will have a larger gape than the HSB.
Posted By: teehjaeh57 Re: Mouth Gape of HSB - 04/15/14 06:04 PM
Wow great data right here. Truly an eye opener to see a 12.75" LMB with the same gape as a 22" HSB. Demonstrates why HSB and SMB are not nearly as effective managing BG populations
Posted By: Bill Cody Re: Mouth Gape of HSB - 04/15/14 07:23 PM
At least for smaller individuals of SMB, HSB, and LMB in my measurements, the difference between the horizontal gape and vertical gape is the vertical gape is about 2mm less than the horizontal. I do have some gape information for other species but let's get this bass mouth gape data accumulated first. Hopefully you members can do some fishing and get us some bass length - mouth measurements. Just about every member has one of these three bass species in their pond. Get out there and catch us a bass for our mouth gape study. Let's fill in the gaps of our data set!
Posted By: Lukkyseven Re: Mouth Gape of HSB - 04/15/14 07:30 PM
Bill,

Maybe this is another post all together, but how much gape would be needed to eat say... BG at 3" 5" 7"? Maybe say the same for YP? This could be other extremely useful information to a lot of us.
Posted By: esshup Re: Mouth Gape of HSB - 04/15/14 07:53 PM
When the fish start biting again, I can take data points for LMB and SMB from my pond. There may be a handful of HSB in there, (I think I've seen some swimming around) but none have ever been caught. I stocked 25 of them 2 years ago, but thought I had a complete kill of the stockers right after stocking.
Posted By: DNickolaus Re: Mouth Gape of HSB - 04/15/14 09:33 PM
Not trying to be argumentative here... Ran across a paper on LMB feeding kinematics. They define gape as the vertical distance from the tip of lower jaw to tip of upper jaw... kinda on an angle with lower jaw further forward. They do have a plot of their gape vs length (Fig 5) They were primarily evaluating kinematics of the capture, not size capacity.
The Journal of Experimental Biology 198, 419–433 (1995)
http://jeb.biologists.org/content/198/2/419.full.pdf
Posted By: fish n chips Re: Mouth Gape of HSB - 04/15/14 09:50 PM
Here is a short post by esshup on HSB gape.

http://forums.pondboss.com/ubbthreads.ph...true#Post343110
Posted By: DNickolaus Re: Mouth Gape of HSB - 04/15/14 10:12 PM
Esshup data July '13:
HSB was 18.25" long, and weighed 3.18# Mouth gape was pretty round, and measured 2"

A few different LMB were measured; here one that was of comparable length, albet 3/4" shorter. 17.5" long, and weighed 3.0# Gape was more oval shape, 2 5/8" high by 3" wide.
Posted By: DNickolaus Re: Mouth Gape of HSB - 04/15/14 11:34 PM
Now here is a very nice paper.
http://www.seafwa.org/resource/dynamic/private/PDF/Hill-47-56.pdf
They do use width and not height for gape.

It indicates that for LMB, gape width = 0.14*Length - 5.59
where dimensions are in mm.
For a 17" fish (largest in their survey), that predicts GW=2.16" which is a .127 ratio.
That is more inline with our SMB data above. They cite the LMB as being from SE FL. Are FL bass different?

Given the results of this study, a peacock cichlid can eat deep-bodied prey of about 30% of its own total length and largemouth bass can eat slightly longer prey (i.e., about 35% of its own length).

For example, a 400-mm TL largemouth bass can eat a 132-mm TL spotted tilapia whereas a 400-mm TL peacock cichlid can eat a
116-mm TL spotted tilapia.


This also seems useful:
BD=body depth (how tall)
TL=total length
both in mm

Bluegill BD=0.46*TL–8.88
Largemouth bass BD=0.25*TL–3.38
Redear sunfish BD=0.40*TL–6.23

Spotted tilapia BD=0.39*TL–0.84
Posted By: DNickolaus Re: Mouth Gape of HSB - 04/16/14 12:15 AM
Still can't find a free online copy of the seminal paper by Johnson & Post (Transactions of American Fish Society 1996) that started this...

Another paper with gape info for LMB. Their point is the pharyngeal gape is smaller and they think that limits prey capture.
http://fishlab.ucdavis.edu/W%26REBF95.pdf
When you do gape/length, they run .18-.19 around 230mm length, 9". They say these data are for FL LMB.

Posted By: Bill Cody Re: Mouth Gape of HSB - 04/16/14 01:16 AM
ewest has access to some good literature in Journals. Let's see what he can provide. Once we know the gape size of various lengths of bass we can do some measuring of prey body depth - height of BG, GSF, Shiners, shad, YP, HBG, etc and create a large very useful data set. We can do our own study and get a good data set if we get enough member participation. Bruce Condello catches a lot of fish and Big fish. He can be a big help with this body length - gape size study. Numerous members catch lots of their pond fish and will be able to contribute some good information. Several duplicate measurements for for the same length of bass is good because it provides variation - variety - diversity. All you members can become amateur fishery biologists.
Posted By: Lukkyseven Re: Mouth Gape of HSB - 04/16/14 01:37 AM
Hey now... I don't mind being a test subject... But biologist? I'll leave that for the smart people. wink
Posted By: Bill Cody Re: Mouth Gape of HSB - 04/18/14 01:35 AM
Is anyone catching HSB or LMB to help with our study of mouth gape for various sizes of these fish?. Don't forget to take along a pen paper and ruler next time you go fishing.
Posted By: canyoncreek Re: Mouth Gape of HSB - 04/18/14 01:55 AM
ruler? for pharyngeal gape I wonder if one of those fancy micrometers that measure the inside diameter of a pipe might be a really handy tool to have in the tackle box smile
Posted By: sprkplug Re: Mouth Gape of HSB - 04/18/14 01:59 AM
I don't normally target bass, but in the interest of science I will see what I can come up with. grin Provided I can leave the bluegills alone for awhile.
Posted By: DNickolaus Re: Mouth Gape of HSB - 04/19/14 06:41 PM
I combined the Hill etal paper above with another I found..
http://nlc1.nlc.state.ne.us/epubs/U1500/T004-2008.pdf
which is a MS thesis from Nebraska. He sampled 2 NE lakes.

Plus a paper from Ball State on Yellow Perch from Lake Michigan.
http://cms.bsu.edu/-/media/WWW/DepartmentalContent/Biology/pdfs/GapeLimitationYEP.pdf



First LMB is the Hill paper. Next 6 lines are the NE MS thesis, and then the last two YP are the BSU work.

FYI, the sample size for the HSB was 168 fish, so a nice population from two lakes.
I'm struggling to believe the YP data though it was 284 fish. They have a very narrow mouth for body length. But I can see no other way to interpret their paper. As I am sending BSU tuition money for my daughter, I may well call one of the authors and inquire.

But, I'm pleased to find some reasonable census measurements for gape!
Posted By: DNickolaus Re: Mouth Gape of HSB - 04/19/14 07:18 PM
And of course, we want to know how our anecdotal data compares..
Looks like we have fish with big mouths. Perhaps small carefully managed BOW vs public?

Posted By: esshup Re: Mouth Gape of HSB - 04/20/14 02:17 AM
I fished the pond today, specifically to measure gape. Here's some data points for you.

All gape measurements are horizontal gape.

YP Male 11" 1.2" 3 fish
10" 1.0" 4 fish
9.5" 9.9" - 1.0" 2 fish

YP Female 12" 1.2" 1 fish
11 3/4" 1.2" 1 fish
11" 1.0"-1.1" 9 fish
9.5" .9" 1 fish

SMB 11" 1.5" 1 fish
11" 1.3" 3 fish
10" 1.2" 1 fish





I have some LMB that I caught and tossed in a cage, and I can net 'em and measure them. Most were 7"-8" but one was around 17".
Posted By: DNickolaus Re: Mouth Gape of HSB - 04/20/14 10:37 AM
Thx for data. Put them on the plot and added the YP curve back. I need to find SMB data in a paper. But should be between HSB & LMB.

Our data seems to put YP down with HSB, not above LMB where BSU paper put em. The shape is more HSBish.

Really makes me wonder about the overall shift between our data and papers. Nobody called me on private vs public water, but that seems a poor theory. Could be genetics or measurement technique?? Discussion welcomed!
Posted By: DNickolaus Re: Mouth Gape of HSB - 04/20/14 11:27 AM
This is a bad sign.. a Willis PhD student allowed to not use SMB gape but instead peacock cichlid. If Willis didn't know of any SMB gape data, how am I going to find it? I'll try to get my hands on the Hill paper and see what it says, and then add the cichla curve.. later today.. tis Easter with a beautiful sunrise and wife's Bday at same time.. I am fixing the dinner.

I estimated smallmouth bass GW using published equations for peacock cichlids Cichla ocellaris (Hill et al. 2004

PS.. a 20" cichlid/SMB with 2.3" vs a LMB at 2.5 while HSB at 1.5".. anyone believe that?

PPS: Willis let a PhD student pull one over on him. The Hill paper does not say SMB=cichlid, it says LMB=cichlid. And that explains the 20" data.

Given the morphological similarity of largemouth bass and peacock cichlids, we predicted that a simple method of estimating gape size used for largemouth bass (i.e., external mouth width; Lawrence 1958, Hambright 1991, Johnson and Post
1996) would also estimate peacock cichlid gape size
Posted By: CJBS2003 Re: Mouth Gape of HSB - 04/20/14 04:25 PM
Peacock cichlids has some good sized mouths.
Posted By: Bill Cody Re: Mouth Gape of HSB - 04/20/14 09:30 PM
You should be able to get all the mouth gape data that you need from the numerous members here that have SMB in their ponds. Some including Bobby Rice go SMB fishing on summer vacation. Lets encourage all of them to take some measurements of SMB they catch this summer. One just has to not be in a hurry for the data.
Posted By: Bill Cody Re: Mouth Gape of HSB - 04/20/14 09:46 PM
Where did you get the mouth gape data for YP? I don't think their mouth size is greater than LMB at least the way I measure mouth gape. Here are some of my measurements of horizontal mouth width for yellow perch: 3"=0.27", 5"=0.59", 6"=0.70", 7"=0.86",
8"=0.94", 9.0"=1.08", 10.0"= 1.10", 11"=1.18". 12"=1.3".
Posted By: DNickolaus Re: Mouth Gape of HSB - 04/20/14 11:34 PM
Thanks for your additional data Bill. I'll add it.

My source is clearly cited for the YP curves- it's from Ball State. And the discussion points out concern. I'll attempt to reach authors.

The beginning of my graduate research was a good literature study. All advanced research should benefit from prior work and sift what is valuable. As you say, we need not be in a hurry and I believe that includes not hurrying to dismiss unexplained data. We may learn valuable things.
Posted By: DNickolaus Re: Mouth Gape of HSB - 04/21/14 08:48 PM
I'm pasting in the emails with Prof Tom Lauer at Ball State. You all can judge for yourselves.

The student author is now a fisheries biologist in Oregon, but she is out on medical leave after she broke her back in a helicopter crash doing a fish survey. I left a msg with her husband in the same office. I am removing the YP curves for now.



Dan
I haven’t measured the largemouth bass gape and couldn’t tell you how yellow perch relates. From your comments, you appear to be questioning our yellow perch measurements. Fair enough. Measuring a few hundred yellow perch and largemouth bass of the same size would provide you with your answer.
Tom Lauer

Thomas E. Lauer, PhD
George and Frances Ball Distinguished Professor of Biology
Director, Aquatic Biology and Fisheries Center
Department of Biology
Ball State University
Muncie, IN 47306
TX: 765-285-8825
Fax: 765-285-8804
Email: tlauer@bsu.edu

From: Nickolaus
Sent: Monday, April 21, 2014 8:43 AM
To: Lauer, Thomas
Subject: RE: Yellow Perch gape

Prof Lauer,
Below is a screenshot of the table upon which I based the plot. Yes, many say that gape is a theoretical maximum prey dimension. I seek the physical dimension of the YP gape, and am not considering prey size. The paper seems to say GHM is a perch gape measurement, but these equations indicate a YP gape larger than that of a LMB when compared to other literature.
Dan

Dan
You plotted the theoretical maximum of the prey species, not the actual ingested prey size. In general, most piscivores will consume prey up to 1/3 to ½ their length. The portion of figure 3 that you did not graph is the actual consumption size. I suspect when you eat, you could take a bigger bite. I also suspect you rarely, if ever, take a bite that fills your entire mouth (the theoretical maximum).
Tom Lauer


Thomas E. Lauer, PhD
George and Frances Ball Distinguished Professor of Biology
Director, Aquatic Biology and Fisheries Center
Department of Biology
Ball State University
Muncie, IN 47306
TX: 765-285-8825
Fax: 765-285-8804
Email: tlauer@bsu.edu

From: Nickolaus
Sent: Monday, April 21, 2014 7:33 AM
To: Lauer, Thomas
Subject: Yellow Perch gape

Good morning sir.
As the father of a BSU freshman, I was pleased to see a BSU paper on a topic I’ve been researching, namely piscivore horizontal gape. I own a pond South of Lake Monroe and have been gaining understanding in developing a stable ecosystem. I’ve gotten involved in a forum called Pond Boss that discusses pond management. I’ve been trying to catalog the gape data for different pond fish, both from academic papers and Pond Boss member measurements. I have found it very interesting but your data from Gape limitation and piscine prey size-selection by yellow perch in the extreme southern area of Lake Michigan, with emphasis on two exotic prey items, Table III has me puzzled. For the sake of discussion, I’ll add my current literature search plot. I did the calculations in mm and converted to inches- but you can see that YP end up above largemouth bass. We all know that isn’t the case, so I thought to seek your input on how I might have interpreted your paper incorrectly. I would expect YP to be around 9-10% GW/LT. If I could reach enlightenment on this quandary and find some smallmouth data, I’d be pleased.

Thank you kindly,
Dan Nickolaus


Posted By: esshup Re: Mouth Gape of HSB - 04/21/14 10:31 PM
Dan:

I've got a start on the YP measurements. Hopefully some other Pond Bossers can help fill in more data. I'll take measurements of LMB in my pond as the season progresses. We had a cold front roll through the area this afternoon, high winds, 10-15 degree temp drop and lightening. I suspect the fish will be harder to catch for the next few days. I'll report more fish as the data is available.
Posted By: DNickolaus Re: Mouth Gape of HSB - 04/21/14 11:28 PM
will be happy to toss in any and all data that floats by.
Once we get a reasonable sample for a species, I can do a linear fit and we can generalize relative gape sizes. That point for the 18" Cody LMB is gonna be an outlying point for any linear fit I fear. smile Reminds me of a few catfish I could put whole hands in.

Symbols are our measurements. The lines are from literature.

Posted By: Bill Cody Re: Mouth Gape of HSB - 04/22/14 01:05 AM
Dan - that the outlying gape for the 18" LMB was a calculated measurement and not an actual measurement. WE need some members to catch 17", 18" and 19" LMB and get some actual measurements.
Posted By: Bill Cody Re: Mouth Gape of HSB - 04/22/14 01:06 AM
Dan - In rechecking my data, I notice that the outlying gape for the 18" LMB was a calculated measurement and not an actual measurement. We need some members to catch 17", 18" and 19" LMB and get some actual measurements and replace my outlying gape estimate datum point.

It is good that Dr. Tom Lauer at Ball State responded to your inquiry.
Posted By: esshup Re: Mouth Gape of HSB - 04/22/14 02:37 AM
I have those size LMB swimming in my pond. But, the mouth gape will be skewed to the small size because most of them should be pellet trained. We need to get the Texas boys in on this thread!
Posted By: DNickolaus Re: Mouth Gape of HSB - 04/22/14 08:38 AM
I will remove that LMB point. It stood out as odd. Thank you for filling us in on that one.

Does gape actually change with environment then? Would have figured it's more genetic then environment. Why would eating pellets reduce mouth/bone growth? Eating full-bite prey stretches it somehow? (Another interesting area of research I've seen in the literature.. why do they eat maximum gape prey? .. seems an energy efficiency thing)

We seem biased to higher mouth sizes than the literature. I'd be happy to see some data on the smaller side.

It was good of Lauer to respond. I didn't feel he answered my question though. Data has to pass a gut-check and should fit into a continuum. It doesn't exist in isolation. When things don't make sense, it is a good thing to probe for explanations.
Posted By: esshup Re: Mouth Gape of HSB - 04/22/14 01:22 PM
Eating pellets allow the fish to grow faster, and it seems that the head doesn't grow as fast. The pellet trained LMB in my pond have big bodies, but small heads. The offspring that are in the pond that aren't eating pellets are more porportional.
Posted By: Bill Cody Re: Mouth Gape of HSB - 04/22/14 01:56 PM
It will be interesting to compare mouth gape for pellet and wild LB.
Posted By: esshup Re: Mouth Gape of HSB - 04/22/14 02:44 PM
I talked to highflyer last night. He's going to collect data on LMB during his get together this Sat and post the numbers. I don't think a lot of the LMB in his pond are pellet trained, but there should be ample live forage for them. He said his WR's were running 120-140.
Posted By: ewest Re: Mouth Gape of HSB - 04/22/14 07:26 PM
I don't think plasticity of gape size will be very high in one generation. In addition all of the pellet trained LMB in ponds I am aware of have natural forage so they don't rely on pellets alone. interesting idea to investigate.
Posted By: DNickolaus Re: Mouth Gape of HSB - 04/22/14 08:28 PM
Would be great to get a slug of data from the Tx Big Do. One could never say for certain that a fish was wholly pellet fed unless you have a single-species pond that is a strict piscivore (upon adulthood), so I don't know how we could try to categorize our data to determine effect of feed/growth.

Would be an interesting MS thesis to do a controlled experiment to determine the effect of feeding & growth rate on relative proportions. But it would be a multi-year effort.

To be fair with the concept, does this not open the opposite possibility that the YP data is correct? If those YP are exceptionally slow-growing in Lake Michigan, no pellet feed, cold winters, short growing season, poor prey source, then would it not follow that for the body length they would have relatively large gapes?
Posted By: esshup Re: Mouth Gape of HSB - 04/23/14 12:20 AM
I'm not sure about YP. With the YP that I've caught, I haven't seen the size difference between feed trained/non-feed trained like I do with the LMB. Why that is, I have no idea.
Posted By: Cray Re: Mouth Gape of HSB - 04/23/14 12:58 AM
I have a LMB only pond and I plan on doing some sampling in a few weeks.
They have had nothing but pellets since I stocked them except for a few tadpoles.
300 were stoked in July of 2012. They were 2" at that time.
Posted By: Bill Cody Re: Mouth Gape of HSB - 04/23/14 01:05 AM
We should be able to get lots of mouth gape data from numerous willing members here. Data from various locations will result in more validity to the data. When I measure mouth gape for a bass I hold it by the lip and measure the distance across the inside of the mouth. Basically what will fit into the mouth without stretching it side to side.
Posted By: Cray Re: Mouth Gape of HSB - 04/23/14 01:25 AM
Ok I will try to get about fifty or so.
Posted By: Cray Re: Mouth Gape of HSB - 04/23/14 01:31 AM
I found this blue gill today when feeding the fish. It looks to have been hit by an LMB. The bite radius looks to be about 5 inches. How long would the bass be? Best guess

Attached picture image.jpg
Posted By: DNickolaus Re: Mouth Gape of HSB - 04/23/14 08:48 AM
Extrapolating from our few measured points, you need a 29" LMB to get a 5" wide gape. The literature only has that length fish at 4" gape. Extrapolating the AL LMB growth curves, you'd get a 12-15 year old fish. The FL curve says 15 yo or so. Per literature, LMB have lived that long, but not the norm. Northern states couldn't get one that long on avg.
Posted By: ewest Re: Mouth Gape of HSB - 04/23/14 02:07 PM
Some northern fish have been aged to the 20s. TPWD did a life span included study on Fla LMB growth in a 17 year study on the same fish.
Posted By: Cray Re: Mouth Gape of HSB - 04/24/14 12:14 AM
Well that would be amazing my longest to date is 26!
Posted By: Bill Cody Re: Mouth Gape of HSB - 05/12/14 04:08 PM
New data point from RC51. LMbass 17" long with mouth gape of 2.75" (width). Thanks RC for remembering. Any others been catching LMB or HSB for some mouth gape measurements?????
Posted By: esshup Re: Mouth Gape of HSB - 05/13/14 12:45 AM
No. I cooked the nightcrawlers in the car yesterday... cry
Posted By: Cray Re: Mouth Gape of HSB - 06/07/14 04:36 PM
We went this morning and had a blast here are the measurements.
21" long
3-5/8" gape

19-1/2" long
3-1/4 gape

10-1/2 long
1-1/2 gape

18-1/4" long
3-1/4" gape

20-3/8" long
3-3/8" gape

21-3/8" long
3-7/16" gape

22" long
3-3/4 gape

17-1/4" long
3" gape

18-1/4" long
3-1/8" gape

19-7/8" long
3-1/4" gape

I will post pics in newly uploaded images.
Posted By: Bill Cody Re: Mouth Gape of HSB - 06/08/14 03:06 AM
Cray - thanks a lot for taking time to make those mouth measurements. They will help our data set of fish mouth gape information. Any others out there willing to help???
Posted By: Bill Cody Re: Mouth Gape of HSB - 06/14/14 08:25 PM
Lovnlivin: measured this HSB: The HSB was 17" with a vertical gape of 2", horizontal gape of 1 5/8".
Posted By: DNickolaus Re: Mouth Gape of HSB - 07/08/14 12:03 PM
Just to tie up loose ends. I have tracked down and had a conversation with the student author of the Ball State paper on YP feeding. Recall the faculty author was less than helpful. She states that all the YP they measured were dead. The mouth gape was measured with digital calipers. They did a max stretch gape both horiz and vert. They inserted the "jaws" of the caliper in the proper orientation and opened them until they wouldn't go any further. She admitted this is not a realistic feeding opening, but was selected as most repeatable among different folks measuring.

We already had concerns about the YP dataset as it showed YP having a larger gape than LMB, but this explains why. As the measurement doesn't really fit our stated gape model, I'll leave that YP data out. Our experts may want to weigh in, but when a horizontal gape is measured, I can see slightly opening the mouth to get inside, but stretching a fish to some unnatural limit seems not fitting.
Posted By: Bill Cody Re: Mouth Gape of HSB - 07/08/14 03:57 PM
Thanks for checking on this and updating us about it. Enlightening informaiton.
Posted By: Bill Cody Re: Mouth Gape of HSB - 09/15/14 02:17 PM
"Just passing some info along. ... 24" CC 4.9lb Mouth width 4" height 3" inhaled a 5.4" bluegill." (from PB Member Snakebite).
Posted By: esshup Re: Mouth Gape of HSB - 10/31/21 01:25 PM
I know it's an old thread, but I am doing some serious culling from my pond this Fall due to the low water level going into winter. I want to reduce the biomass in the pond and have a target goal of 60# of fish to remove. Mostly HSB, but all LMB caught will be removed and any fish that is bleeding too. Do we still need gape data? If so that can be recorded. I am recording length/weight data already.
Posted By: Bill Cody Re: Mouth Gape of HSB - 10/31/21 10:10 PM
Gape data is always useful. The more data points the better and more reliable the information becomes. Thanks for taking time to do it.
Posted By: esshup Re: Mouth Gape of HSB - 11/01/21 04:24 AM
O.K. Bill. Will do. Now the question is how do you want it measured? Hold mouth open measure height or width or both or what?

What species of fish?
Posted By: FishinRod Re: Mouth Gape of HSB - 11/01/21 02:03 PM
I think we need a uniform set of plastic "reference" bluegill.

"The #8 bluegill barely fit into the subject HSB's mouth. The #9 would not fit."
Posted By: Bill Cody Re: Mouth Gape of HSB - 11/02/21 01:38 AM
Measure any that you have time for. Mostly when gape is measured they use width. Height and width are similar length with width being usually about 1-2 mm longer. I would pull the mouth open although I do not put undue "stress" stretching the mouth open. This stretching it open is somewhat subjective.
Posted By: esshup Re: Mouth Gape of HSB - 11/02/21 05:23 AM
Originally Posted by Bill Cody
Measure any that you have time for. Mostly when gape is measured they use width. Height and width are similar length with width being usually about 1-2 mm longer. I would pull the mouth open although I do not put undue "stress" stretching the mouth open. This stretching it open is somewhat subjective.

Bill:

Plenty of time to measure. I have a buddy's 11 yr old kid that is a fishing fool and since I don't have enough time to fish the pond to remove fish I am paying him "X" amount per pound for certain species to be removed, and "X" per pound for other species that are released back into the pond. The caveat for him is that he has to log every fish caught: Date, species, weight/length, whether kept or released and I can add gape to the list. I have a "Rite in the Rain" notebook and the pen that goes with it, a folding fish ruler and a digital scale like they use during Major League Fishing tournaments. All of this is kept in a container that he can easily access and put away when done. I even have a rubberized landing net for him to use.

The goal is to remove 60# of fish before the winter with the focus on Largemouth Bass 1st, HSB 2nd. (2x the $$ for LMB vs HSB LOL) Released fish are paid at 50% the rate of HSB. (all per pound). His eyes lit up when I asked him if he wanted to get paid to fish, BUT he had to keep a detailed record of what he caught. He was all for it.
Posted By: ewest Re: Mouth Gape of HSB - 11/02/21 03:56 PM
A great learning experience for all - well done !!
Posted By: FishinRod Re: Mouth Gape of HSB - 11/02/21 04:37 PM
"Plenty of time to measure. I have a buddy's 11 yr old kid that is a fishing fool and since I don't have enough time to fish the pond to remove fish I am paying him "X" amount per pound for certain species to be removed, and "X" per pound for other species that are released back into the pond."

esshup,

At that age, I would have PAID YOU to have that job!

You probably need to add "Evil Genius" to your profile!
Posted By: RStringer Re: Mouth Gape of HSB - 11/02/21 05:16 PM
Isnt there a song about a "Nickle for turning in bass never have to worry about the price of gas".
Posted By: Sunil Re: Mouth Gape of HSB - 11/04/21 01:39 PM
Rusto, yes, there is, however the most recent revision has "Nickle" replaced with "Gold Kruggerand."
Posted By: esshup Re: Mouth Gape of HSB - 11/05/21 01:28 AM
Originally Posted by FishinRod
"Plenty of time to measure. I have a buddy's 11 yr old kid that is a fishing fool and since I don't have enough time to fish the pond to remove fish I am paying him "X" amount per pound for certain species to be removed, and "X" per pound for other species that are released back into the pond."

esshup,

At that age, I would have PAID YOU to have that job!

You probably need to add "Evil Genius" to your profile!

LOL His Dad said he couldn't keep quiet on the ride home. Now he told his Dad to bring him here when his Dad comes here to go hunting. "I wont hunt, I want to fish while you hunt."

I got the rest of the supplies in the mail the last few days so I will have everything set up for this weekend for him. I won't be here - got way too many fish to pick up and throw in ponds.
Posted By: RStringer Re: Mouth Gape of HSB - 11/05/21 02:59 PM
Realized my bad spelling struck again after the fact oh well. I have lots of flaws in my game lol.
© Pond Boss Forum