Pond Boss Forums INTRO Questions & Observations Fish longevity as a function of water temperature

I recently received a copy of an article from Norman Kopecky (BTW, thanks Norman) concerning longevity of various life forms, including fish and how the temperature of their environment affects life span. This article, called "Life On The Scales" was fascinating and shed quite a bit of light on the questions some of us have been asking ourselves about why a bluegill in Indiana might live twice as long as a bluegill in Texas.

I'd like Norman to tell us what publication this came from and comment on it's content. I think it really clarifies some issues on how long our pond fish will live and may also invite some comment from other forum members as to whether or not artificial feeding of fish affects life span.

Don't you just love it when you get interested and it's one of those TO BE CONTINUED!

Norm, where are you before I go nuts with anticipation!

Very interesting concepts. I am also I am very interested if this article appeared in a peer refereed professional journal. Was research involved or was it thoughts and conjecture of the author?. Please give us some more facts Norm. How can we see a copy of it?

Bruce and Cecil, this article was from the February 12, 2005 issue of SCIENCE NEWS pages 106 to 108. www.sciencenews.org This is a weekly magazine that covers all areas of science. Another great magazine (British weekly)is NewScientist. www.newscientist.com I also sent copies of the article to Dave Willis and Bob Lusk and they can probably comment better than I.

Here's the basic idea. Animal life forms appear to be able to only live so long. In this article, the authors attribute this to damage to DNA by free radicals. Other articles attribute this to the gradual break down of telemeres which are segments at the end of DNA chains. When the telemeres are about gone, the DNA corodes and then the cell is killed. It appears that this is what aging is all about. From what I read, the telemere theory appears to be a more important factor than free radicals although the theories might be tied together.

The rate that all of this occurs is determined by the rate of metabolism. Fish in the north with lower metabolism rates live longer than fish in the south with higher metabolism rates. Higher temperatures produce higher metabolism rates. "There is a universal biological clock but it ticks in units of energy, not in units of time".

The authors have used this equation to explain everything from cancer growth rates to amount of time we sleep to the spacing of trees and branches and of course, how long things live. Scientist also use this formula to understand subcellular molecules to global ecosystems to the Earth's carbon cycle to hatching times in the eggs of birds, fish, amphibians and plankton.

For anyone that likes to work with abstract ideas, I hightly suggest you look this article up on the web or e-mail me at nkopecky@iw.net and I will send you a copy.

Bill, both ScienceNews and New Scientist are weekly magazines summarizing professional research. Yes, all of the articles quoted as making up this summary are from very prestigious peer reviewed magazines. In the real world, there is always some conjecture, nothing is ever totally nailed now. This is true of even such basics as time and gravity. Even the definition of when something is dead or alive is totally arbitrary and not agreed upon.

For anyone that enjoys reading about general science on a professional level, I highly recommed these two magazines. If you want me to send you a copy of the article, e-mail me at nkopecky@iw.net

If anybody's interested, I'm writing a comment on this subject. I'd also like to make available copies of this article for other forum members to see. If I get your name and address I'll make more copies so that everyone can see what we're talking about. I think this is relevant subject matter to anyone who is interested in how long fish live in our ponds and why. I've been at an aquaculture conference this weekend with Dr. Joe Morris as the key speaker trying to learn how to grow some of our fish indoors. I learned quite a bit if anyone wants to discuss findings.

Bruce

Bruce:

Do you have these 3 pages available to email?
Thanks, if not I will forward my mailing address.

Rowly

I don't have them in a form that can be e-mailed but I'd be happy to run a hard copy and mail it to you.

"Science News" also has this report on how harvest pressure can promote smaller, slower growing fish.

http://www.sciencenews.org/articles/20050226/fob4ref.asp

This page outlines the article and sources. I'll have to look this over and maybe incorporate it into our theories on fish aging and growth in our ponds.

I've read through the article about six times now and I can't say that I've got a terrific grasp of the concept, but here goes...

Researchers have long known that metabolic rates of animals bear a rather predictable relationship to the animals' size. Simply put, you can predict an animal's heart rate, respiration rate, and general aging to what's known as quarter power scaling laws. This is a little tedious, but an animal's metabolic rate is proportional to mass to the 3/4 power and it's heart rate is proportional to mass to the -1/4 power. Because of this faster metabolic rate, a shrew squeezes in as many breaths and heart beats as an elephant during their lives. They gestate quickly, sexually mature quickly--and die more quickly.

An animal's metabolic rate is determined by how efficiently it delivers fuel to its cells. A relationship exists between the blood vessels of an animal and the surfaces that they supply. The greater height, width and depth of a large animal gives the myriad of vasculature the ability to deliver fuel to the cells and sweep up free-radicals more efficiently than the smaller animal. What are free radicals? Glad you asked. Biochemical reactions involved in metabolism produce dangerous by-products called free radicals which gradually degrade cellular quality by binding to the DNA and damaging it's ability to replicate and do its chores correctly. (Believe me, that last sentence was a ridiculous oversimplification that if some physician reads this they'll be laughing their butt off right now).

Biochemical reactions and all chemical reactions in general take place over time, but not time as we generally think about it. Biochemical time is HEAT. Heat drives reactions as surely as you're sitting here reading this. Hotter cells' reactions occur more quickly. A fish that's sitting under the ice in a pond that's not supercooled by a poorly placed aerator (Reference for regular forum readers) has an extremely slow metabolism. Its heart is barely beating and, in effect, is not really aging. The biochemical reactions that aren't occuring aren't producing free radicals, so the aging process isn't really happening the same way it does for a warm blooded animal. Even in the forsaken icebox that some people refer to as Nebraska my body temperature is about the same as it is for somebody basking on his porch in Whitesboro, Texas. These two people are aging about the same, but the fish in their respective ponds aren't.

I saw a study in In-Fisherman lately that stated some of the smallmouth bass caught in a tournament up north were aged at 22-24 years old! Can you imagine that?! I'll bet there's no smallie in the history of Texas that lived that long. Unfortunately all this extra life doesn't necessarily equate to greater growth because a cold fish doesn't eat as much.

Maybe the only really practical application that I can derive from this knowledge is that if I kill the fish in my pond it takes a lot longer to recover. That's just me whining though. At least we've got great football.....oh, well...maybe we don't even have that anymore.

Bruce,

Yeah, Sounds like a trade off -- do you want a fast growing fish that dies younger or a slower growing fish that lives longer and reaches about the same size in some cases?

Record wise, at least for fish that are native to both the southern lattitudes and the northern lattitudes, not withstanding subspecies or now separate species status as in the Florida Largemouth, it seems a faster growing fish albeit a shorter lived ends up the biggest.

However, one has to wonder if you can at least have a little of both. Case in point; Florida bass or Florida bass hybrids in California in waters that have cool enough water to holdover rainbow trout. From what I have heard these bass are inhabitiing cool enough water to forage on rainbow trout. Maybe the cooler water is giving them more longevity? We all know how big these fish are.

I have to wonder if my record perch, which as a species is acclimated to cooler northern water, is growing optimally in summer due to a prolific food supply and optimum temps (pond is cooled a little but overflow from trout pond), but has it's life span lengthed by cold winters, which btw it's acclimated to obviously if you consider they need those cold winters to develop their eggs.

But then again these perch are just under 5 years age and they may end up living shorter lives due to the fast growth rate. Time will tell.

On this subject I do remember talking to a biologist in Wisconsin about their Seeforellen strain of browns that have a propensity to break the world record for brown trout. For those of you that don't know, this is a strain of lake run browns from Bavaria that were imported into the US in the 80's by the state of New York. Anyway, the conjecture was they would not live as long due to the relatively warmer water in Lake Michigan vs. their natural waters. Turns out they are living just as long last I talked to the biologist. Look for the world record for brown trout to be broken in one of the Great Lakes.

Perhaps this is a subject for another time but at the aquaculture conference there was quite a buzz amoungst the yellow perch enthusiasts about how much difference in growth potential there is between separate strains of yellow perch. I'm sure you have no interest in this subject however. :rolleyes:

Bruce, thank you for that great summary. This article explains size and longevity in general. This is only in general and is usful in studying systems.

We're interested in growth and size in individuals. If I go off the deep end here, please someone correct me. The things we read about in nutrition for people often apply to fish as well. The metabolism of food does a number of things for us. It provides energy for movement not only in the enviroment but also for body parts such as the movement of our hearts. It provides the energy needed to metabolize more food. It provides the materials for growth. It provides the energy to fight off various diseases and parasites. It provides the materials and energy to fix body parts that have been damaged.

The individual has only so much "heat time". The more of this "heat time" that is used for other things, the less there is left for growth. To grow the biggest, we try to limit the amount of energy going to other things. Part of that is diet. The easier food is to obtain and the more energy derived from it, the bigger the fish will grow. Trout will provide more energy per unit of energy expended than will crayfish.

In humans, in general, we value longevity and health rather than size. It costs a lot of "heat time" to carry around excess weight, to force blood through all of these extra blood vessels etc. As we use up "heat time" this way, we reduce longevity. If we eat food that absorbs free radicals, there are less free radicals left to destroy DNA.

This is my general understanding of the application of the "heat time" theory. What we do now is look at all of the different ways we can reduce the energy needs for other purposes so that more energy can be spent on growth in fish.

"The things we read about in nutrition for people often apply to fish as well."

Did any of you guys know that if bass get too many carbohydrates (feed trained bass) in their diet they can suffer from the same health problems humans do? That is they become diabetics. Sounds crazy but this is what Dr. Paul Brown of Purdue a reasearcher on nutrition has told me. Bass can get a condition know as fatty livers due to much storage of the carbs. Interesting that a low carb diet is recommended to lose weight and for diabetics. The wife has lots quite a bit of weight on a low carb diet. Dr. Brown says fish can become "functional diabetics" in that they can handle it better than humans.

Bruce you're right. Perch don't interest me one bit!

One thing to remember about going hog wild on whether various strains of perch that grow faster. One of the southeastern strains is supposed to have the fastest growth rate, but it's possible it would not perform as well in outdoor ponds in the north.

Bruce just got an email from my perch producer. He's says to keep a heads up for about March 14th for perch pickup. Did you get my email about the redears?

Guys,
As many of you know, I have been working on a cool project in upstate NY, creating a world class fishing program for a landowner. One goal on a list of many is to improve sizes and growth rates of largemouth bass. Our goal is lofty, to produce double digit bass there. (Unheard of in private waters in NY) To that end, we have feed trained bass there, with roughly 1/6th Florida influence. These fish were stocked at 1/2 pound each, 1200 head, into a four acre pond last May. We set up four automatic feeders, set them to go off every eight hours. Harvested the fish November 6, and brought them inside, into a closed, recirculating system, temperature mid-60's. When the fish were harvested, average length was 13 inches, average weight 1 pound 7 oz. We have fed them all winter, sampled last week. Bass now weigh an average of 1 lb. 12 oz. They range in size from 12 oz. to 3 pounds. The fish are less two years old. Essentially, we are trying to "buy" six or seven years of "normal" NY growth in two years. Our intent is to re-stock bass this spring, into the four acre pond, re-set the feeders, add several hundred pounds of forage fish, and see what happens for another year. Then, once these footballs hit the 4-6 pound mark, we intend to stock them into a 105 acre lake. By then, they will be accustomed to feeding both on pelleted feed and forage fish. Is this risky? Sure, but that's what risk takers do. The unknown variables will be interesting to follow. One...will these bass, pampered and fed in moderate temperature waters, thrive in a "normal" NY lake which freezes? We'll see. Two...will they adjust to such a less pampered life in a lake with tiger muskies, small largemouth bass, limited forage fish, crappie and yellow perch? We'll see. It's new ground. Our theory is to use some of the laws of nature to our advantage in that region of the country. It's "outside the box" thinking, and a number of people are paying attention. For someone like me, it's exciting to work with a landowner who will push the envelope and test things. How does this apply to this thread? This project studies how metabloism, heart beats...natural things affected by climate, temperatures, regional food chains, etc...can be adjusted, or nudged if you will, by a group of managers not willing to accept status quo. As this process goes, we'll let you know the progress.

Bob,

You know what's interesting related to that? Massachusetts a state one over from New York averages larger largemouths than my state of Indiana that is lower in lattitude. Massachusetts state record is 15 lbs. 8 oz. and was not pellet fed. We are up to 14 lbs now but our state record was much lower for many years.

I have lived in both Massachusetts and Indiana and I can tell you bass do average larger in size in Massachusetts even though the waters in Massachusetts tend to be more acidic and softer.

The only thing I can figure that may make these bass grow larger is Massachusetts plants a lot of put and take trout in just about every body of water. Could these fish be getting big on trout as they do in Florida?

Maybe something genetic too. Who knows?

We do know they are naturalized there and not native. Who knows where the original stock came from.

wow!

Thanks Bob/Bruce/Cecil, etc. It is threads like this that have me addicted to this web page.

Cecil, I think the trout could play a major part in the larger sizes. I think you pointed out earlier something about the growth of California bass with plentiful trout as food. In Texas, trout are stocked a lot of places in the winter on a put and take basis. They will die when the water temp increases in the Spring. One of the places they are stocked is below Possum Kingdom Resorvoir dam. The fishing for large stripers is never better than at trout stocking time. A Game Warden once told me that the big stripers accounted for 80% of the trout stocked. Of interest is that the area of the Brazos River below that dam is not particularly well known for big stripers. Nor do they bite all that well until the trout are dumped in. BTW, the Game Warden is there to give tickets to anyone using trout for striper bait. He said he thought it was stupid but he was there enforcing the law.

Do trout have better forage value (protien) than other forage?

Dave,

They have a higher oil content and probably fat. In Europe where the same northern pike we have get much bigger, their forage base has fish with a higher oil/fat content. At least that is one possible explanation according to some biologists. Genetically these pike are the same circumpolar.