Editing Whale (section)

===Locomotion===<!-- [[Whale sounding]] links here -->
[[File:GreenlandWhaleLyd3.jpg|thumb|Skeleton of a [[bowhead whale]]; notice the vestigial [[pelvis]]. [[Richard Lydekker]], 1894]]
Whales have two flippers on the front, and a tail fin. These flippers contain four digits. Although whales do not possess fully developed hind limbs, some, such as the sperm whale and bowhead whale, possess discrete rudimentary appendages, which may contain feet and digits. Whales are fast swimmers in comparison to seals, which typically cruise at 5–15 kn, or {{convert|9|–|28|kph|mph}}; the fin whale, in comparison, can travel at speeds up to {{convert|47|kph|mph}} and the sperm whale can reach speeds of {{convert|35|kph|mph}}. The fusing of the neck vertebrae, while increasing stability when swimming at high speeds, decreases flexibility; whales are unable to turn their heads. When swimming, whales rely on their tail fin to propel them through the water. Flipper movement is continuous. Whales swim by moving their tail fin and lower body up and down, propelling themselves through vertical movement, while their flippers are mainly used for steering. Some species [[Cetacean surfacing behaviour|log]] out of the water, which may allow them to travel faster. Their skeletal anatomy allows them to be fast swimmers. Most species have a [[dorsal fin]].{{sfn|Reidenberg|2012|p=508}}{{sfn|Klinowska|1991|pp=122–262}}

Whales are adapted for diving to great depths. In addition to their streamlined bodies, they can slow their heart rate to conserve oxygen; blood is rerouted from tissue tolerant of water pressure to the heart and brain among other organs; [[haemoglobin]] and [[myoglobin]] store oxygen in body tissue; and they have twice the concentration of myoglobin than haemoglobin. Before going on long dives, many whales exhibit a behaviour known as sounding; they stay close to the surface for a series of short, shallow dives while building their oxygen reserves, and then make a sounding dive.{{sfn|Norena et al.|2000|pp=181–191}}