Sperm whale of the Society for Marine Mammalogy, the largest international association of marine mammal scientists in the world, officially uses "Physeter macrocephalus" when publishing their definitive list of marine mammal species. The sperm whale is the largest toothed whale, with adult males measuring up to long and weighing up to . By contrast, the second largest toothed whale (Baird's Beaked Whale) measures and weighs up to . The Nantucket Whaling Museum has a -long jawbone. The museum claims that this individual was long; the whale that sank the "Essex" (one of the incidents behind "Moby-Dick") was claimed to be . A
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