Is an orca a whale or a dolphin, or is it simply a fish? The striking black-and-white animal often called the killer whale is neither a fish nor a true whale in the strictest sense; it is a marine mammal and the largest member of the oceanic dolphin family.Biological features make the classification clear: orcas breathe air through a blowhole, are warm-blooded, give live birth and nurse their youn...More