Alan: On average, a mature Ocean Sunfish - the world's largest bony fish - weighs 2000 pounds, with peak specimens weighing twice that much.
Since the giant Ocean Sunfish is huge, "snail-slow" and without any known defense mechanism, I once wrote the Monterrey Aquarium asking how it could survive in a world where predators are always on the lookout for A Big Meal.
A Monterrey scientist wrote back saying he didn't know.
Given the fundamental "evolutionary rules" of predation and "survival of the fittest," this singularly unfit fish begs scientific study to find out why it did not become extinct.
Which begs another question: how was the Ocean Sunfish able to evolve over geological time in the first place?
"By adulthood, Ocean Sunfish have the potential to grow more than 60 million times their birth size, arguably the most extreme size growth of any vertebrate animal. "