You guys have the hang of it now.

Sometimes the fastest growing fish get eaten first because they are a little to aggressive or don't get the food they need because the plankton is not there at the right time. But they are going to try to max their energy in vs. energy used.

Yes reproduction plays a big part in several ways. The biggest male BG get the prime interior nest sights and most female attention (eggs). The females in the best entergrtic condition will have the most eggs all things considered. Thus the best BG have the best chance of passing on their genes. But reproduction comes at a cost of less growth. That is one reason Bruce's all male BG ponds have such big males , delayed reproduction/maturity and thus longer period of initial growth. Why - good genes and less energy used in spawning = better growth maximization.

Jeff asks - Therefore would not a male fish have some "instinct" (not sure if that is the appropriate terminology) to become as large and as strong as possible? Absolutely. For several reasons 1) to avoid being eaten , 2) to max their ability to eat others/food , and 3) to pass on their genes and 4) to avoid (out grow) competitors. These are the basic drivers but in all of these the fish are trying to max energy efficiency as best they can.

The even more fascinating aspect is when its applied to the whole pond. It applies to all energy flow including plants , animals and their use of energy. Kinda like what Bruce and Todd were talking about WRT GC but on a larger more involved model.