Following up on our shoebill post, here is the African lungfish. These carnivorous fish have two lungs which allow them to breathe should water become scarce. One of their primary predators is the shoebill. They can't complain, though. These fish are known for having nasty temperaments, and will attack nearly anything that moves - including the nutballs who keep them as pets (I would like one, too, but their too expensive).
Photo courtesy: www.aqualandpetsplus.com.