Quote:
Originally Posted by nightfighter
Still don't get why a big fish is such a more significant breeder than a mid 30 inch fish that has its longer life ahead of it to breed.... Human females produce a finite number of eggs in their lifecycle, and then no more. (learned this from ten years of infertility when I was married)Why would this not be true with fish?
|
Someone answered already, but I'll elaborate. First, fish - and many other animals - are not like humans. They go on reproducing until they die. Fish just drop eggs in the water, so there's no need to spend years raising young. Just as importantly, the fish that reach the biggest size are 1. female, and 2. the oldest. Taking number one first, in population biology its females that are important.
When biologists to the math of reproduction, they literally don't count males. One male can fertilize multiple female's eggs, but each egg is needed to produce a new fish, so females are the important ones in reproduction. When you want to cull a population, like deer, you should really be shooting only does, not bucks.
The second issue is also really important in its own way. The biggest/oldest fish are the ones who have survived all of life's challenges. They are the most resistant to disease and infection, they survived their juvenile years of predation by larger fish, they've proved they can migrate up and down the coast, they can succeed getting food, etc. All of this proves that they have good genes. It's those genes you want in the next generations.
Think of it this way - if you owned an NFL team, would you want to stock your team with players from the college draft, or pick them from Pop Warner teams and wait for them? Some of the best Pop Warner players
might become great pros, but most will never even play college ball. But players who have lasted the longest in organized ball and proved themselves in all levels of competition are the best bet. It's like that in life generally. And that's why I'm in favor of taking an occasional mid-sized keeper and leaving the big cows in the water.