Greg,
I agree. All the literature I have seen says northern bass live longer, but obviously have a shorter growing season. We allegedly have bass that live 15 or 16 years up here. They look like torpedos with an oversize head and razor thin keel by then, but they are old.
I have to wonder if there is some competitive axe to grind here with American Sportsfish. He also has a low opinion of the Georgia Giants, but I have actually seen scientific data recently that shows faster growth with the GG's vs. regular green sunfish hybrids. After seeing some GG's up close I believe they have some shellcracker in them which would explain an ultimate larger size -- but who knows?
I do have a lot of respect for this biologist though.