Pond Boss Forums INTRO Questions & Observations fish, iguanas, just thinking

Ok, last nite I was watching a film on Galapagos marine iguanas. Researchers have found that during times of poor food production, la nina/los ninos cant remember which, the biggest iguanas have the ablility to shrink their skeletons and body size but then are able to regain their stature when food returns. Thinking outside the box, is that possible for stunted fish?

That's an interesting question.

Dave Willis told me once that if a largemouth bass was 15 inches long, it had to have acheived a minimum of a certain weight, but I can't remember what it was.

His point was that if you have a really skinny 15 inch LMB, that it was big enough to acheive that length, so it must have lost weight.

If you follow my logic, this would mean that fish don't lose length when they starve, they just lose weight.

I probably just confused the issue, so go ahead and shoot holes in it.

Right nutrition at the right time.

If an adult person is 6 ft and 250lbs and then starves down to 150 he is still 6 ft.

But if he is born with the genes for 6 ft but as a child gets starvation rations he may only grow to 5'5 due to lack of bone growth .

We have discussed the potential for stunted fish. I will try to find it later. IIRC if conditions for growth improve then growth will resume but they will never reach their genetic potential ( as they would in a balanced /fertile pond). The question becomes are you better off starting over or just reduce the # of stunted fish and move on. If it is a temporary food shortage I would not start over but would fix it as the situation would not have effected their genetics. However if it is a longer term (several generations of stunted fish) situation where the possibility of stunted fish genes or conditioning may exist then it is a different call for me.

Toby, was that the same film that that showed the iquanas grazing for seaweed(?) in the shallow bays, and when they'd try to go back on shore, the seals would swim up behind the iquanas and grab them by the tail and pull them back of shore a few feet.

The seals would just repeat this over and over again. Every time the iquanas were almost on shore, the seals would pull them back out a few feet.

If that was the same film, it's one of the funniest nature shots of all time.

I wanna Iguana taco.

....sorry, I think I just experienced a Cabo San Lucas flashback.

I'm feeling better now.

Mas Tequila at the Cabo Wabo?

Hey Sunil,
no it wasnt but I have seen that one and it is funny in a sick, predator/prey kind of way. The genetics thing though has me thinking. Is it actually possible to change the genetics in your pond in a few generations? Feed, oxygen that promotes growth but I dont thing that it is really possible to change the actual Genetic growth of fish in a few generations. Doesn't genetic change take a couple of million years or so?
Toby

I once saw Stacy Keach turn into an Iguana after just a few days.

i dont know, i think mr. dr. frankenbruce has acheived mutations of the wildest kind in only a couple growing seasons

where is that darn pic...

ahhh, here it is:

Among the vast diversity of traits and genes in a population, it is possible to selectively reinforce for certain traits and have them become the dominantly present genotype in a relatively few generations. In a natural setting, the dominant color pattern of that salt-and-pepper moth in England changed from light (historically) to dark (after the industrial revolution, to match coal soot), and now back to light (much less coal being burned nowadays).

In situations with intended human intervention, this is how we got Manx cats, Chihuahua dogs, and Condello-strain BG.

Theo,

Being such fast and prolific breeders, I have often wondered why lepomis are not selectively bred more that they are. Aside from drosophila, I can't think of a better or easier subject for selective breeding.

I think all the years fiddling with hybrids that do not breed true would have been better spent on selective breeding.

Seems to me that all a breeder would have to do would be to bin the fish every month. Throw out say 95% of them, keep 5%, and breed them with others with the desirable traits. I would guess that you could have strains that are equal or superior to hybrids such as GG within 50 generations or so. 50 generations might only take 10 years.

As Theo notes it all depends. In traditional Mendelian genetics in plants it did not take long. Because most changes in nature (natural settings) are slow, genetic change often matches that rate ( which can be little or none). However when natural changes are fast we see extinction (dinosaurs) or quick adaptation (Theo's moth). Where man intervenes with high fish densities and stunting in ponds over several generations I would be cautious. That might start the selection process in favor of small fast maturing BG.

Bob very interesting. You are describing Bruce's work on CSBG. Private hatcheries have been doing that for years. You would be surprised at the newness of genetics in Fisheries. Genetic testing is in its infancy wrt fish. The question often becomes what is better. Larger , faster , more prolific , color change adaptation , cold tolerant , there are so many variables. By selecting for size or growth in one situation may not give a better fish . Some of the geneticists are providing a warning in their writings about fish that we (assuming the new genetically improved fish get into the normal population) are taking unknown risks with nature. For example stocking fish outside their native populations (including Fla LMB). Until we know a lot about the total BG genome we don't know all the changes that are occurring. What if selecting for large size reduces fitness for avoiding disease or color change ? Have we then made a better fish ? BTW I support what Bruce is doing and your though just pointing out we don't know very much and should think about possible consequences. The reason we have not seen more work is the costs are high to do genetic research and the field is new and there is little money to be made in fish. People first and things people require (the human genome and food plants and animals first).

I would say that even before Bruce and anyone else started selecting BG for size and growth, we were already forcing a selection. If nothing else, stocking fish from hatcheries must have at least partially selected for BG that transport better and with fewer morts. The emphasis on forage base for LMB ponds (which I think is still probably the most common pond management scheme) may well have selected BG with higher fecundity.

Continued divergence along such lines could give us the BG equivalent of Wolfhounds and Corgis to go with the Chihuahuas. Quite capable of interbreeding, but optimized for different purposes.

ewest,

I wasn't really thinking of a state-sponsored program. I was thinking of the "big numbers" route, like chicken ranchers use.

With lepomis being such prolific breeders, the young could be sorted monthly, right up to full growth. Any that stand out for any reason would be separated, and added to newer and newer breeding populations. It seems that it wouldn't take very long to have a populaiton of super fish. The sheer numbers of offspring greatly accelerate that process. When you deal with millions of eggs, you're bound to get a few super fish to beef up the population. Endlessly catching and sorting fish sounds too work-intensive for me. I was hoping you would do it while I cheer you on!

We can all cheer Bruce on !!! Go Bruce Go.

Ok,
But wait...are Bruce's giants actually genetically changed or his creation of the perfect growing environment causing the effect? Take grass seed....throw some on the driveway and then throw some on a pile of cow poop. Same genes but holy cow look at the crap grass grow!!!
Toby

Damn it I wish I was going to Texas in March

Toby, a gene is a locatable sequence on a DNA strand that corresponds to an inherited trait or characteristic.

I'm not changing the genes, I'm just selecting for certain characteristics, which may make some genes (such as rapid growth or affinity for pellets) show up more frequently in a population.

The ultimate hope is that you take a population of bluegill which has two or three really fast growing fish out of a hundred, and end up with a group of fish which has fifteen or twenty such fish. I may not live long enough to see any incredible results, but it's a good mental exercise just the same.

If the next generation has more of the "super growers" than the previous one, then I'll have more fish to stock in my ponds and give to my friends.

At the end of the day, putting them in a "perfect environment" will make most bluegill into super growers, I'm just stacking the odds in my favor, and maybe that gene sequence for a three pounder ends up living a perfect life and achieving the maximum possible growth. Then I can catch the fish and hold him way out in front of me for a photograph that makes him look like he's four pounds.

Hey Bruce,

I think your approach has the potential to seriously improve genetics. I think 3 pound bream is not only possible, but realistic.

Considering what has been done with dogs and horses in 100 years, I think there is the potential to develop super strains of bream in 100 months. Of course one would need 3 or 4 ponds and a rigorous binning program.

Texas Parks and Wildlife has added a new twist to there Share a lunker program. For those not familiar with there work, for years they have collected 13lb plus female LMB caught in the state and used them for a year in their selective breeding program. After one year the donor can have them back to release or dispose of at their choice. The State also gives you a free fiberglass replica of your fish. They have started raising males from the offspring of the lunker female offspring to breed to future lunkers and will release these offspring in select public reservoirs that are smaller impoundments known for their lunker growing capabilities. DNA mapping will be used to confirm parentage. Their ultimate goal is to break the 20lb barrier and then the world record. There were several release sites on the list but I can only remember two, Lake Raven @ Huntsville Sate Park and lake Pinkston east of Nacogdoches.

Here you go FT.

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