Earth is the pelagic planet and the principle apex predators of that realm for the last few hundred million years have been sharks. As it is presently understood, sharks go back through the fossil record some 400 million years. As far as the fossil record shows, sharks represent the earths first fully jawed vertebrates. Sharks live today in essentially the same structure, form and function as in the times preceding the rise and fall of the dinosaurs. Sharks in very similar forms to shark of today actually predate trees.
Sharks are a cosmopolitan species, with many makes and models.
The endothermy, electro-sensory apparatus, and the optics of several species are all better than top of the line, they are superlative. Indeed a 1200 lbs mako shark slow cruising the open seas at 6 knots certainly represents an apex predator at the top of the food chain, a trophic juggernaut, but sharks can also be found at all levels of that vast chain. Whether the setting is benthic, pelagic, sub-tidal, or estuarine, there is a specialized shark for that environment. From the tiny cigar shark to the massive whale shark, sharks are a formidable biotic mode. Sharks are nearly impervious to infections, cancers and circulatory diseases and have shown the ability to heal and recover from severe injuries while healing rapidly.