Sleep in aquatic mammals Sleep in non-human animals

northern sea lion pup adult female , male, largest of eared seals. habitat: northern pacific.

the consequences of falling deep sleep marine mammalian species can suffocation , drowning, or becoming easy prey predators. thus, dolphins, whales, , pinnipeds (seals) engage in unihemispheric sleep while swimming, allows 1 brain hemisphere remain functional, while other goes sleep. hemisphere asleep alternates, both hemispheres can rested. terrestrial mammals, pinnipeds sleep on land fall deep sleep , both hemispheres of brain shut down , in full sleep mode. aquatic mammal infants not have rem sleep in infancy; rem sleep increases age.

among others, seals , whales belong aquatic mammals. earless seals , eared seals have solved problem of sleeping in water via 2 different methods. eared seals, whales, show unihemispheric sleep. sleeping half of brain not awaken when surface breathe. when 1 half of seal s brain shows slow-wave sleep, flippers , whiskers on opposite side immobile. while in water, these seals have no rem sleep , may go week or 2 without it. move onto land switch bilateral rem sleep , nrem sleep comparable land mammals, surprising researchers lack of recovery sleep after missing rem.

cape fur seal, asleep in zoo

earless seals sleep bihemispherically mammals, under water, hanging @ water surface or on land. hold breath while sleeping under water, , wake regularly surface , breathe. can hang nostrils above water , in position have rem sleep, not have rem sleep underwater.

rem sleep has been observed in pilot whale, species of dolphin. whales not seem have rem sleep, nor seem have problems because of this. 1 reason rem sleep might difficult in marine settings fact rem sleep causes muscular atony; say, functional paralysis of skeletal muscles can difficult combine need breathe regularly.