How do dolphins and other water bound mammals sleep?

Question

By water bound i mean that they live only in the water such as dolphins and whales. The only way i can imagine them doing it is if they floated at the surface with their blowholes out of the water. But then they have to contend with waves, storms and the chance that they might roll over in their sleep and drown.

Answer 1

Dolphins can shut down one side of their brain while laeving the other side up and running. This allows them to maintain breathing functions (they are voluntary breathers unlike humans) as well as maintain their sensory capabilities like sight and echolocation. As for sleeping on the surface, some dolphins will sleep under the water and come up for air when necessary. Some will float in a small area while others will go into a resting pattern (slow swimming pattern). When one side of the brain is rested up, it will come back on and the other side will turn off. The dolphin will do this throughout the day and pick up 8 hours of sleep through collective napping times. I believe whales function in the same manner.

Manatees can hold their breath longer. When they rest, they will settle to the bottom of their environment (usually someplace shallow like a riverbed or close to shore depending on their location) and stay their. Every so often, the manatee will rise straight to the surface, take a breath of air, and sink back down to its resting spot.

Sea lions (when in the water) can sleep in congregations called "rafts" because they actually lay on each other, forming a bed of sea lions to help keep them afloat. Seals, due to their antisocial nature, will "bottle" in the water when they sleep. That means when the seal is sleeping, its head is above the water, while its body remains below vertically. Walruses, when in the water, exhibit the bottling technique as well.

Answer 2

The dolphins sleep in two ways: horizontal or vertical usually with another dolphin beside them,answering the details of your question the dolphins spend 33.4% of the day sleeping so when storms and waves comes they don't drown beacause they have the control of its espiraculus, espiraculus is a type of skin desing to open and close under the control of the dolphin.
A dolphin can breathe 8 to 12 times per minute when it is swiming and active and 3 to 7 times per minute when they sleep. Other way they sleep is by been in the surface and usually that position can be easily confuse with a wood log stick.
Actually they don't die by the cause of drawning, but they can die when they are been stalked by other animal and they suffer a panic attack that make them swim more in the bottom making them die, also when they stay traped in a fishing net the die by sofocation

Answer 3

Dolphin Sleep Habits:

Dolphin's sleep by either resting quietly in the water or by swimming slowly next to another animal.

When dolphins swim next to another animal to sleep it is called logging. This is because they look a lot like logs floating in the water.

When dolphins swim and sleep at once it is similar to when people nap.

Dolphins use shut off half of their brain when they sleep. The other half of the brain is used to watch for predators. This half of the brain also controls the blow hole.

Dolphins must keep their blow hole functioning. If they didn't, it would be the same thing as if human were to turn off their nose and mouth. They need to be able to breathe while sleeping.

Dolphins generally sleep at night but only for a few hours at a time.

http://www.msu.edu/~durbinre/dolphinsleeping.htm

Answer 4

What is "wrong" with breathing air and living in the ocean? The sea turtles have been doing it before the dinosaurs even evolved, and they are still around. The ichthyosaurs breathed air (they were reptiles) but they lived in the ocean. The sea snakes breathe air and they live in the ocean. The sea otters, seals and sea lions are all mammals. They breathe air and they live in the ocean. Of course the penguins live in the ocean but they breathe air. If an animal can find food, survive and reproduce in the ocean, then it has succeeded in its struggle for survival. The fact that whales have been around for about 50 million years is testimony to their success. Dolphins and whales unquestionably evolved from land animals. There are fossil animals that are clearly related to whales but they have limbs. Whales still have forelimbs, and they still show vestiges of their rear limbs. In fact, about a decade ago, paleontologists found a fossil whale that has the characteristic limb bones of artiodactyls, the even-toed ungulates. Even before that, DNA evidence has shown that whales are closely related to hippos, cows, and goats.

Answer 5

Marine mammals manage to sleep in the ocean by having half their brains working at all time while asleep. This monitors their breathing and directs them to come up to the surface when in need of a breath.

Answer 6

Yes they do sleep but they do not fully shut down their brain so they still know to come up for air.

We were also doing a study on Manatee sleep cycles at our zoo wondering the same thing. With manatees it is more that they sleep but only for short periods of time before they need to rise for air again.

Answer 7

they close down half their brain. this might be a very ancestral characteristic as duck billed platy pusses (pussi?) also do this.
But they don't sleep in bunk beds they sleep on the river bed.

Answer 8

Dolphins need to read a few pages of a book first to help them doze off. Whales on the other hand are notoriously heavy sleepers but they like to settle down in sunken pirate ships where it's a bit more peaceful.

Answer 9

Dolpins shut down one half of their brain at a time to sleep so that they remember to go up for air.

Answer 10

They sleep like Luco Brassi - with the fishies