"Whales range in size from the blue whale, the largest animal known to have ever existed at 35 m (115 ft) and 150 tonnes (150 LT; 170 ST), to various pygmy species, such as the pygmy sperm whale at 3.5 m (11 ft)."
"Whales collectively inhabit all the world's oceans and number in the millions, with annual population growth rate estimates for various species ranging from 3-13%. For centuries, whales have been hunted for meat and as a source of raw materials. By the middle of the 20th century, however, industrial whaling had left many species seriously endangered, leading to the end of whaling in all but a few countries."
- ^ Mead, James G.; Brownell, Robert L., Jr. (16 November 2005). "Order Cetacea (pp. 723-743)". in Wilson, Don E., and Reeder, DeeAnn M., eds. Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Baltimore: Johns Hopkins University Press, 2 vols. (2142 pp.). ISBN 978-0-8018-8221-0.
- ^ Brown, Lesley, ed (2007). Shorter Oxford English Dictionary. II (Sixth ed.). Oxford: Oxford University press. pp. 3611.
- ^ http://www.acsonline.org/education/taxonomy.html
- ^ "What is the biggest animal ever to exist on Earth?". How Stuff Works. Retrieved 2007-05-29.
- ^ "Whale Population Estimates". International Whaling Commission. March 2010. Retrieved March 2010.