" The downside to F1's is that as they interbreed in the long run you end up with F2,F3,F4,FX..etc These latter generations lack the hybrid vigor of the first cross and ultimately without the supplementation of genetics in the long run you will end up with fish that has no extraordinary genetic characteristics and is similar to what you would find naturally.
I don't believe this to be accurate - IMO. This has been covered before on the Forum. Lack of hybrid vigor comes from outbreeding depression and occurs in the FX offspring of crosses of 2 different species (not within a species) ie hybrid Bluegill ( a GSF X BG cross). . .
IMHO I think both of the ideas are correct (and incorrect) in part. Breeds, Lines, and Varieties are all examples of artificially selecting for a predictable standard for life like dogs, fish, and tomatoes. These standards have highly concentrated genes that produce a great degree of variety of traits within a species (for example chihauhuas and great danes). Usually when inbred lines of different standards are bred together, the F1 offspring produced are fairly consistent in terms of their traits. But the FX generations do show a high degree of variability. If the F1 was very desirable, often efforts are undertaken to select for the F1 traits and produce an inbred variety that consistently produces offspring that are like the F1s. This can only be done through artificial selection as nature will itself go the path that favors those traits that contribute most to reproductive success. If the breeder is very good at identifying the desired traits he can usually produce a variety, breed, or line with traits that are consistent with the F1 generation in about 7 to 9 generations.
I think most people over anticipate the level and consistency of selection from recreational fisheries suppliers than they would expect from tomato seed supplier, for example. I think the most pertinent traits are shaped by natural selection factors in what seem to be regionally superior traits. Here regionally superior means that the trait contributes to reproductive success over the long haul in the waters these fish have evolved. In a recreational pond, the traits that win are those that favor reproductive success and after 7 generations the genes will reflect what contributed most to reproductive success. If aggressiveness, then we will see that trait (as we do in the North). Faster growth and slower metabolism seem to be important to survival and reproductive success in the South. I think each pond is its own laboratory and one very important environmental influence is the human predator contribution of fishing and culling/harvest. There is only one way to remove this influence on traits of a population of the adult fish. One would need to eliminate the dependence on natural reproduction for trophy path recruits.
