I think that along with the ideas about size length of life is something we as fish keepers need to look at. If you keep a sturgeon and it gets to be four feet long (lets say that it it's maximum size) and it lives to be five years old no chest thumping will convince me you did a good job, that fish was capable of living several decades. If it lived five years and reached it's maximum size something was wrong with the way you kept it. I think a better rule of thumb for keeping fish is the length of it's life not it's maximum size.
