World's Largest Living Animal

The blue whale (Balaenoptera musculus) is a baleen whale that filters krill from seawater. NOAA reports that some large individuals may consume as much as roughly six tons of krill a day, illustrating the scale of their feeding requirements.

Blue whale size varies across populations: NOAA notes that Antarctic blue whales tend to be larger than North Atlantic or North Pacific animals, with some reaching around 110 feet (roughly 33.5 metres) in length. Females are generally larger than males. The species occurs across the world's oceans apart from the Arctic, but population movements vary.

Commercial whaling severely depleted blue whale populations. The species is protected and listed as endangered under the US Endangered Species Act, but vessel strikes, fishing-gear entanglement and ocean noise remain threats. This record compares the approximate body mass of exceptionally large members of a species, not the weight of every individual.