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The paradox was to figure out how dolphins can obtain such high speeds and accelerations with what appears to be a small muscle mass. Gray made an estimate of the power a dolphin could exert based on its physiology, and concluded the power was insufficient to overcome the drag forces in water.
A great cormorant swimming. Aquatic locomotion or swimming is biologically propelled motion through a liquid medium. The simplest propulsive systems are composed of cilia and flagella. Swimming has evolved a number of times in a range of organisms including arthropods, fish, molluscs, amphibians, reptiles, birds, and mammals.
A common bottlenose dolphin (Tursiops truncatus). A dolphin is an aquatic mammal in the clade Odontoceti (toothed whale).Dolphins belong to the families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the New World river dolphins), Pontoporiidae (the brackish dolphins), and possibly extinct Lipotidae (baiji or Chinese river dolphin).
A beautiful pink dolphin, who was first spotted in Louisiana in 2007, was again seen swimming through a ship channel in her native state.
The dolphins drive a school of fish towards the shore where humans await with their nets. In the confusion of casting nets, the dolphins catch a large number of fish as well. Intraspecific cooperative foraging techniques have also been observed, and some propose that these behaviours are transmitted through cultural means.
The Irrawaddy dolphin is a slow swimmer, but swimming speeds of 20–25 kilometres per hour (12–16 mph) were reported when dolphins were being chased in a boat. [11] In a year, females can sometimes swim as fast as average of 45 km, males can swim up to average of 100 km. [ 12 ] : 2
Oceanic dolphins are fast swimmers in comparison to seals who typically cruise at 11–27 km/h (7–17 mph); the orca, in comparison, can travel at speeds of up to 55.5 km/h (34.5 mph). The fusing of the neck vertebrae, while increasing stability when swimming at high speeds, decreases flexibility, which means they are unable to turn their heads.
Although river dolphins do not possess fully developed hind limbs, some possess discrete rudimentary appendages, which may contain feet and digits. River dolphins are slow swimmers in comparison to oceanic dolphins, which can travel at speeds up to 35 miles per hour (56 km/h); the tucuxi can only travel at about 14 miles per hour (23 km/h). [26]