Blue whale

The blue whale is the largest known animal to have ever existed.[3][13][14][15] The International Whaling Commission (IWC) whaling database reports 88 individuals longer than 30 meters (98 ft), including one of 33 meters (108 ft), but problems with how the measurements were taken suggest that any longer than 30.5 meters (100 ft) are suspect.[16] The Discovery Committee reported lengths up to 31 meters (102 ft);[17] however, the longest scientifically measured individual blue whale was 30 meters (98 ft) from rostrum tip to tail notch.[18] Female blue whales are larger than males.[5][19] Hydrodynamic models suggest a blue whale could not exceed 108 ft (33 m) because of metabolic and energy constraints.[20] The highest recorded weight for the species is 199 metric tons (196 long tons; 219 short tons).[16]

The average length of sexually mature female blue whales is 22.0 meters (72.1 ft) for Eastern North Pacific blue whales, 24 meters (79 ft) for central and western North Pacific blue whales, 21–24 meters (68–78 ft) for North Atlantic blue whales, 25.4–26.3 meters (83.4–86.3 ft) for Antarctic blue whales, 23.5 meters (77.1 ft) for Chilean blue whales, and 21.3 meters (69.9 ft) for pygmy blue whales.[16][21][22]