"What if we could find an animal that thrived in a factory-farm cage, one that subsisted on nutrients plucked from the air and that was insensate to the slaughterhouse blade?" asks Christopher Cox. "Biologically, oysters are not in the plant kingdom, but when it comes to ethical eating, they are almost indistinguishable from plants. Oyster farms account for 95 percent of all oyster consumption and have a minimal negative impact on their ecosystems."