Killer whale Killer whale The killer whale or orca ("Orcinus orca") is a toothed whale belonging to the oceanic dolphin family, of which it is the largest member. Killer whales have a diverse diet, although individual populations often specialize in particular types of prey. Some feed exclusively on fish, while others hunt marine mammals such as seals and other species of dolphin. They have been known to attack baleen whale calves, and even adult whales. Killer whales are apex predators, as no animal preys on them. A cosmopolitan species, they can be found in each of the world's oceans in a variety
Omura's whale Omura's whale Omura's whale or the dwarf fin whale ("Balaenoptera omurai") is a species of rorqual about which very little is known. Before its formal description, it was referred to as a small, "dwarf" or "pygmy" form of Bryde's whale by various sources. The common name and specific epithet commemorate Japanese cetologist . The scientific description of this whale was made in "Nature" in 2003 by three Japanese scientists. They determined the existence of the species by analysing the morphology and mitochondrial DNA of nine individuals – eight caught by Japanese research vessels in the late 1970s in the Indo-Pacific