Pond Boss Magazine
https://www.pondboss.com/images/userfiles/image/20130301193901_6_150by50orangewhyshouldsubscribejpeg.jpg
Advertisment
Newest Members
Benny carnivore, Cohiba767, ThePondScum, JimjB, TNPondo
17,777 Registered Users
Forum Statistics
Forums36
Topics39,782
Posts541,579
Members17,779
Most Online3,583
Jan 15th, 2020
Top Posters
esshup 26,757
ewest 21,016
Cecil Baird1 20,043
Bill Cody 14,287
Who's Online Now
4 members (FishinRod, jpsdad, catscratch, Snipe), 205 guests, and 166 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Page 2 of 2 1 2
Joined: Apr 2002
Posts: 14,287
Likes: 183
B
Moderator
Ambassador
Field Correspondent
Lunker
Offline
Moderator
Ambassador
Field Correspondent
Lunker
B
Joined: Apr 2002
Posts: 14,287
Likes: 183
FishinR - I also am a novice at examining otoliths. I have removed several otoliths but never attempted looking at any of them. Removal can be a little tricky at least for me. Trained people do otolith extraction of 1"-2" fish. I would really like to see that one performed. Lusk should produce a step by step article for the process of extracting otoliths from several fish species. Then do an article step wise about examining the otoliths. Big Bump to the PBoss editor. Get 'er done.

If one would do 50 to 100 from several species, removal would seem to be rand look relatively easy. But if you don't know what you are doing,,, it is not quite so easy. I equate it to playing the piano or an instrument. If you know how it is EASY. If you don't how it seems pretty difficult. "Practice makes perfect". I tend to have a hard time locating the otolith chamber.

I know my perch habits well enough after years of working with them. So for the pellet feeding study, I used 3 obvious age classes of known age FEMALE perch. So I can monitor the ages of the YP basically by size.
Mixes of males and females will grow at different rates. Thus one is not sure of the age class just by looking at and measuring the fish.

Last edited by Bill Cody; 01/16/22 01:47 PM.

aka Pond Doctor & Dr. Perca Read Pond Boss Magazine -
America's Journal of Pond Management
1 member likes this: Stressless
Joined: Jan 2009
Posts: 26,757
Likes: 334
Moderator
Ambassador
Field Correspondent
Lunker
Offline
Moderator
Ambassador
Field Correspondent
Lunker
Joined: Jan 2009
Posts: 26,757
Likes: 334
^^^ I agree with Bill on the age vs size thing. I caught a 13" YP from my pond last year in early Spring. Looked kinda plump, thought it was a female. Nope. it turned out to be a male when I cleaned it.

There were people from SDSU at one of the PB conferences doing otolith removal and aging. They sure made it look easy and quick. Zip out it came, they cracked it in half and looked at it under the microscope.


www.hoosierpondpros.com


http://www.pondboss.com/subscribe.asp?c=4
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).
Joined: Nov 2007
Posts: 1,565
Likes: 262
F
Lunker
Online Content
Lunker
F
Joined: Nov 2007
Posts: 1,565
Likes: 262
Thanks Bill and esshup!

Almost everything looks "easy" when an expert is doing it!

Good data is the key to good studies, but I hadn't read much of people using otoliths on the forum to get correct ages. So I figured it was probably difficult for novices.

If we do have a resident expert, could they make a side hustle of performing that service for members?

Joined: Oct 2018
Posts: 1,717
Likes: 219
S
Snipe Online Happy OP
OP Online Happy
S
Joined: Oct 2018
Posts: 1,717
Likes: 219
It can be done but having the proper equipment to do it is tougher than one may think. We pull otoliths from WAE every year for age study. I've done it with 2 perch about 5" long and it's a job. It's very easy to destroy the otolith if you haven't had some training.
They are dried and wiped clean, then set in a small receptacle that resin is poured into. When it sets hard the mold is sawed in half through the otolith. The cut is cleaned and placed under magnification and they appear somewhat like rings of a tree yet a bit more complex. Most Biologists are looking at year class but the trained eye can get down to within a week-accurately.

1 member likes this: FishinRod
Joined: Nov 2007
Posts: 1,565
Likes: 262
F
Lunker
Online Content
Lunker
F
Joined: Nov 2007
Posts: 1,565
Likes: 262
Thanks Snipe.

That is very similar to how I used to process geological samples for microscope studies.

Relatively easy when you have a lab with all of the equipment.

Way too costly in time/money if you don't have a processing facility.

Joined: Apr 2002
Posts: 14,287
Likes: 183
B
Moderator
Ambassador
Field Correspondent
Lunker
Offline
Moderator
Ambassador
Field Correspondent
Lunker
B
Joined: Apr 2002
Posts: 14,287
Likes: 183
Snipe's otolith description is why I haven't done it yet; due to being too busy with other things that I know more about.

Last edited by Bill Cody; 01/17/22 12:00 PM.

aka Pond Doctor & Dr. Perca Read Pond Boss Magazine -
America's Journal of Pond Management
Joined: Oct 2018
Posts: 1,717
Likes: 219
S
Snipe Online Happy OP
OP Online Happy
S
Joined: Oct 2018
Posts: 1,717
Likes: 219
Bill, you would have no trouble getting your head wrapped around the growth patterns. Part of the reason otoliths are used now is due to the fact you can determine growth rates as well as year class. Something that can't really be seen when using scales.

Joined: Mar 2005
Posts: 21,016
Likes: 140
E
Moderator
Hall of Fame 2014
Lunker
Offline
Moderator
Hall of Fame 2014
Lunker
E
Joined: Mar 2005
Posts: 21,016
Likes: 140
Originally Posted by FishinRod
Bill,

Are you doing final age determinations on the fish by examining otoliths?

If so, how easy is that process to perform by novices?

It is not easy for experienced examiners and certainty not for novices. It is worth a try, but results are not fully reliable for exactness.
















Joined: Oct 2018
Posts: 1,717
Likes: 219
S
Snipe Online Happy OP
OP Online Happy
S
Joined: Oct 2018
Posts: 1,717
Likes: 219
ewest, I'm intrigued by your "not fully reliable for exactness" comment.. Can you elaborate a bit on what you mean there?

Joined: May 2018
Posts: 1,584
Likes: 202
J
Online Content
J
Joined: May 2018
Posts: 1,584
Likes: 202
Originally Posted by Snipe
ewest, I'm intrigued by your "not fully reliable for exactness" comment.. Can you elaborate a bit on what you mean there?

Its easy to destroy/miss information in samples especially that of the early years particularly if/when the growth was small. One must view in cross section and so this requires intersecting the 0-year.

There are number of methods for aging fish (e.g. scales, spines, and otoliths). They all work by the same principle, seasonal growth causes the growth darker margins where growth is subdued. Provided the subdued growth is annual, then counting the rings is an indication of age. I am not aware of any real world conditions where fish are developing more than one ring per year but it is in principle possible. Generally, rings indicate a minimum age that can be taken as true but it is possible that age is underestimated.

I've read that spine collection can miss early growth and that usually field samplers try take spine as far below the outer surface as practical without unduly harming the fish. Spines are often preferred due to the ease of sectioning (the collected sample is sectioned for example). Like otoliths, growth rings are preserved over time. Scale growth can destroy information of early life.


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: 21,016
Likes: 140
E
Moderator
Hall of Fame 2014
Lunker
Offline
Moderator
Hall of Fame 2014
Lunker
E
Joined: Mar 2005
Posts: 21,016
Likes: 140
Agree with jpsdad on what the studies show. This is especially so in warmer climates as the rings do not separate as well when there are not strong distinct seasonal weather changes.

Don't get me wrong on this however - they are good sources and experts can do amazing things with all of the aging sources.

Last edited by ewest; 01/20/22 11:38 AM.















Joined: Mar 2005
Posts: 21,016
Likes: 140
E
Moderator
Hall of Fame 2014
Lunker
Offline
Moderator
Hall of Fame 2014
Lunker
E
Joined: Mar 2005
Posts: 21,016
Likes: 140
FYI - aging info - be sure to note location

Neal et al. Invalidation of Otolith Ageing Techniques for Tropical Largemouth Bass
Otoliths have been used to determine individual age of many species of fish in different regions of the world (Warburton 1978, Erickson 1983, Summerfelt and Hall 1987, Crawford et al. 1989, Brothers 1990, Fowler 1990). For temperate regions, an nual growth checks (annuli) in otoliths have been validated for many species, and are generally related to seasonal changes in water temperature and corresponding changes in the growth rate of the fish (Williams and Bedford 1974, Bagenal and Tesch 1978, Jearld 1983, Schramm 1989). In sub-tropical regions, such as Florida, accurate ageing of centrarchids using otoliths has been accomplished where scales have been shown to lose their validity (Hoyer et al. 1985, Crawford et al. 1989, Schramm 1989). The same is true for temperate fishes such as walleye (Stizostedion vitreum), for which otoliths are preferable to scales and spines for age determination (Erickson 1983). Ageing of tropical fish using otoliths has not enjoyed the same success as in temperate regions (Pannella 1980, Longhurst and Pauly 1987). This inadequacy is due to a lack of discernible or interpretable patterns on otoliths, possibly resulting from the lack of variation in environmental conditions affecting growth rates (Pan nella 1980). However, fish ages obtained from otolith annuli have been verified in some tropical marine fish families, including Lutjanidae, Serranidae, Lethrinidae, and Sciaenidae (Fowler 1990). Largemouth bass are not native to the tropics or marine environments, but they have been widely introduced into freshwater reservoirs in tropical regions. For age and growth studies of largemouth bass in temperate and sub-tropical regions, annuli from whole and sectioned otoliths have been verified (Miller and Storck 1982, Taubert and Tranquilli 1982, Hoyer et al. 1985, Crawford et al. 1989). Yet, there is no evidence in the literature of validation studies of ageing techniques for tropical large mouth bass. As sport fish management increases in Puerto Rico, so does the use of otoliths as an indicator of fish age without proper validation. This study was under taken to assess the utility of otoliths for age and growth analyses of largemouth bass populations in a Puerto Rican reservoir.

For the entire sample, only 14% (5 of 36) of the otoliths exhibited opaque bands that correctly identified largemouth bass age. Although true age only spanned 3 years, ob served ages from otoliths often missed the true age by 2 years, and average ageing error was 1.25 years.
















Joined: Oct 2018
Posts: 1,717
Likes: 219
S
Snipe Online Happy OP
OP Online Happy
S
Joined: Oct 2018
Posts: 1,717
Likes: 219
I can see that being an issue where seasonal changes are less pronounced, definitely would make it much tougher to read.
It's my understanding that's why KDWP got away from scales due to inaccuracies. Fish grown in Hatchery conditions from a known hatch date, then scale samples were not really depicting proper age structure on a consistent basis..

Page 2 of 2 1 2

Link Copied to Clipboard
Today's Birthdays
There are no members with birthdays on this day.
Recent Posts
Orangespotted Sunifsh
by jpsdad - 06/29/22 10:31 PM
Proud moment
by Snipe - 06/29/22 09:56 PM
What did you do at your pond today?
by TGW1 - 06/29/22 08:06 PM
Lots of forage, stop or keep feeding
by Snipe - 06/29/22 04:25 PM
How to dig out a settlement pond?
by John Fitzgerald - 06/29/22 02:56 PM
Large Tilapia displacing BG from nests
by anthropic - 06/29/22 08:46 AM
Thoughts on a new 2.7 acre pond stocking
by Heppy - 06/29/22 07:17 AM
Building Docks in Northern Waters for Ice-Out
by Journeyman - 06/29/22 07:03 AM
Controlling weeds around pond
by Snipe - 06/29/22 12:32 AM
New Pond Construction in Watkins Glen, NY
by Retired on 40 - 06/28/22 08:19 PM
Bluegill growing like crazy and LMB cull part III
by 1997pond - 06/28/22 04:17 PM
50+ year old 1/2 AC farm pond
by PAfarmPondPGH69 - 06/28/22 02:35 PM
Newly Uploaded Images
Male RES
Male RES
by Shorty, June 27
New Record Bluegill
New Record Bluegill
by Theo Gallus, June 10
pond 6
pond 6
by Stressless, May 10
Molly Ann surveys her new Puppydom
Molly Ann surveys her new Puppydom
by Mongos Pond, January 28
Fry
Fry
by CityDad, January 20
Baldcypress
Baldcypress
by Stressless, January 11

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

Powered by UBB.threads™ PHP Forum Software 7.7.5