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C&R Perpetuates Naive Genes?

Blog by: Lloyd Tackitt 11/16/2017
I was reading, in a book about fly fishing for Sunfish and Bass, that studies show that Bass have different genetic traits when it comes to aggressive feeding and innate learning ability.  It should come as no surprise, although I'd never thought of it previously, that some Bass are more genetically pre-disposed to take lures than other Bass - they are naive to put it nicely - and they don't learn fast or well.  Other (smarter) Bass are more finicky about taking their food and they also learn quickly to avoid lures.  The studies showed that these traits are passed on to off-spring as well.

So (in a no doubt over-simplification), there are two categories of fish.  Smart ones and dumb ones.  Dumb ones are generally easier to catch.  Smart ones are generally harder to catch.

When we catch and release fish, we are more likely than not releasing a dumber fish that will perpetuate its dumber genes. 

It is a novel thought to me that we aren't just returning a fish to breed, we are quite possibly missing an opportunity to improve the overall intelligence level of the fish population by removing the dumber ones since the dumber ones are the one we are most likely to catch.

I'm for C&R.  I'm also for improving the fish's overall intelligence and wariness.  Looks like we are caught in a conflict of interest with no way out though.  Imagine what hatchery fish do to the overall fish population in this regard.

It's an interesting concept that has been scientifically studied and the outcome ascertained - that every fish we put back is more likely than not to be one of the slow learning naive fish and that putting it back perpetuates the dumber genes.  

Blog content © Lloyd Tackitt
Blog Comments
rkhancock, CO   11/16/2017 6:50:40 PM
Good read! This brings an interesting thought to my mind. Are "dumber fish" bigger because they are more aggressive and tend to eat more, and bigger, prey? It would be interesting to see the difference in size between the two categories.
bron, CO   11/16/2017 7:55:48 PM
I read that fish, in general, have almost no memory retention. I know the ones in my fish tank think they are hungry a half hour after they are fed. I watched Toadfish catch a MA grasscarp 20 minutes after he had just released it.
Lloyd Tackitt (Lloyd Tackitt), TX   11/17/2017 6:55:26 AM
I've read that goldfish have a 3 second memory. Not sure where that came from. I know that the fish in my fishing area learn and learn fast. If I use just one fly they will quit biting it in a matter of a few hours. Then if I switch to another fly I start catching fish again, but they soon learn about it. A week later and I can catch them on the first fly again, but only for a few minutes. A week later and I may not catch any at all on that fly.
illpilgrim, CO   11/17/2017 9:37:25 AM
The more naive the better lol... more catching right? How smart is the smartest fish in CO? Probably not that smart in the end, but more so lazy and weary. Even the big ones still get fooled by little pieces of metal flying by. CNR of "dumb fish" would not perpetuate dumb genes because.. if a fish is caught it could diminish the fitness of that individual. Perhaps by physically damaging it, making it available to predation, or maybe causing some lapse in normal behavior. If the "smart" fish remain untouched their chances at survival should be greater than that of the dumber individuals. I would predict that a fish's size is a good indicator of its intelligence. If it weren't smart it would already be dead. Unless there are no predators, in which case I would assume the fish that eats the most will grow the most. Of course, if you are to kill the individual then the impact is clear. Assuming we kept everything we caught only the smartest would survive. But let's not genetically cleanse the fish. lol
shiverfix, CO   11/17/2017 1:34:06 PM
There has actually been a lot of research into fish memory. I much prefer to cite the original studies, but am not finding them with a quick search (I miss having access to a college's online library). This article actually hits on three of them. The study by researchers at the Technion Institute of Technology in Israel is the most commonly cited in articles about fish memory.
Dave Mauldin, TX   11/17/2017 4:48:58 PM
My favorite: a big school of big dumb ones