Whale morphology shows several examples of convergent evolution, the most obvious being the streamlined fish-like body shape. [29] Other examples include the use of echolocation for hunting in low light conditions— which is the same hearing adaptation used by bats— and, in the rorqual whales, jaw adaptations, similar to those found in pelicans, that enable engulfment feeding. [30]

IWC. "Small cetaceans". International Whaling Commission. Archived from the original on 21 March 2017 . Retrieved 8 April 2018. The references include Wikipedia, Cambridge Dictionary Online, Oxford English Dictionary, Webster's Dictionary 1913 and others. Details can be found in the individual articles. Purves, P. E. (1955). "The wax plug in the external auditory meatus of the". Discovery Reports. 27: 259–273. Marrero, Meghan E.; Thornton, Stuart (1 November 2011). "Big Fish: A Brief History of Whaling". National Geographic. Archived from the original on 11 October 2015 . Retrieved 2 September 2015. Whales are the largest animals on Earth and they live in every ocean. The massive mammals range from the 600-pound dwarf sperm whale to the colossal blue whale, which can weigh more than 200 tons and stretch up to 100 feet long—almost as long as a professional basketball court.About 34 million years ago, a group of whales began to develop a new way of eating. They had flatter skulls and feeding filters in their mouths. The extinct whale species Perucetus collossus (described in 2023) may have rivalled or exceeded the blue whale in size, with an estimated mass of 80 to 340 tons, and its average estimate of 180 tons surpassing the average blue whale's mass of 100 to 130 tons (but not the largest individual blue whale ever found). [3] Several extinct dinosaurs may also have reached a similar mass to the blue whale. [4] Whole genome sequencing suggests that blue whales are most closely related to sei whales with gray whales as a sister group. This study also found significant gene flow between minke whales and the ancestors of the blue and sei whale. Blue whales also displayed high genetic diversity. [12] Hybridization

Gohar and colleagues analyzed the fossils in the lab of Hesham Sallam, founder of the Mansoura University Vertebrate Paleontology Center and the study's senior author. The study was published online Wednesday (Aug. 25) in the journal Proceedings of the Royal Society B: Biological Sciences. Brain size was previously considered a major indicator of the intelligence of an animal. Since most of the brain is used for maintaining bodily functions, greater ratios of brain-to-body mass may increase the amount of brain mass available for more complex cognitive tasks. Allometric analysis indicates that mammalian brain size scales at approximately the ⅔ or ¾ exponent of the body mass. Comparison of a particular animal's brain size with the expected brain size based on such allometric analysis provides an encephalisation quotient that can be used as another indication of animal intelligence. Sperm whales have the largest brain mass of any animal on Earth, averaging 8,000 cubic centimetres (490in 3) and 7.8 kilograms (17lb) in mature males, in comparison to the average human brain which averages 1,450 cubic centimetres (88in 3) in mature males. [61] The brain-to-body mass ratio in some odontocetes, such as belugas and narwhals, is second only to humans. [62] Timeline: The History of Whaling in America". American Experience. PBS. Archived from the original on 1 May 2010. Bortolotti, D. (2008). Wild Blue: A Natural History of the World's Largest Animal. New York: St. Martin's Press.The IWC has designated two whale sanctuaries: the Southern Ocean Whale Sanctuary, and the Indian Ocean Whale Sanctuary. The Southern Ocean whale sanctuary spans 30,560,860 square kilometres (11,799,610sqmi) and envelopes Antarctica. [109] The Indian Ocean whale sanctuary takes up all of the Indian Ocean south of 55°S. [110] The IWC is a voluntary organization, with no treaty. Any nation may leave as they wish; the IWC cannot enforce any law it makes. Cooke JG (2020) [errata version of 2020 assessment]. " Eubalaena glacialis". IUCN Red List of Threatened Species. 2020. e.T41712A178589687. doi: 10.2305/IUCN.UK.2020-2.RLTS.T41712A178589687.en. The blue whale is usually solitary, but can be found in pairs. When productivity is high enough, blue whales can be seen in gatherings of more than 50 individuals. [11] Populations may go on long migrations, traveling to their summer feeding grounds towards the poles and then heading to their winter breeding grounds in more equatorial waters. [59] The animals appear to use memory to locate the best feeding areas. [60] There is evidence of alternative strategies, such as year-round residency, and partial (where only some individuals migrate) or age/sex-based migration. Some whales have been recorded feeding in breeding grounds. [61] The traveling speed for blue whales ranges 5–30 kilometers per hour (3.1–18.6mph). [11] Their massive size limits their ability to breach. [62] The newly discovered 10-foot-long (3 meters) species, dubbed Phiomicetus anubis, was a beast; When it was alive more than 43 million years ago, it both walked on land and swam in the water and had powerful jaw muscles that would have allowed it to easily chomp down on prey, such as crocodiles and small mammals, including the calves of other whale species.

This five-metre-long animal had proper flippers and tiny hind legs. It lived entirely in the water and was a good swimmer. It also gave birth to its young underwater.Australia/Indonesia population – Whales in this region appear to winter off Indonesia and migrate to their summer feeding grounds off the coast of Western Australia, with major concentrations at Perth Canyon and an area stretching from the Great Australian Bight and Bass Strait. [24] University of Vermont (12 October 2010). "Whale poop pumps up ocean health". Science Daily . Retrieved 18 November 2011. Captive whales have occasionally been known to mimic human speech. Scientists have suggested this indicates a strong desire on behalf of the whales to communicate with humans, as whales have a very different vocal mechanism, so imitating human speech likely takes considerable effort. [56] The blue whale's diet consists almost exclusively of krill. [11] Blue whales capture krill through lunge feeding, they swim towards them at high speeds as they open their mouths up to 80° [11] [63] They may engulf 220 metric tons (220 long tons; 240 short tons) of water at one time. [67] They squeeze the water out through their baleen plates with pressure from the throat pouch and tongue, and swallow the remaining krill. [11] [63] Blue whales have been recorded making 180° rolls during lunge-feeding, possibly allowing them to search the prey field and find the densest patches. [68] Scholander, Per Fredrik (1940). "Experimental investigations on the respiratory function in diving mammals and birds". Hvalraadets Skrifter. 22: 1–131.