How do whales and dolphins sleep without drowning?
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Observations of bottlenose dolphins in aquariums and zoos, and of whales and dolphins in the wild, show two basic methods of sleeping: they either rest quietly in the water, vertically or horizontally, or sleep while swimming slowly next to another animal. Individual dolphins also enter a deeper form of sleep, mostly at night. It is called logging because in this state, a dolphin resembles a log floating at the water's surface.\nWhen marine mammals sleep and swim at once, they are in a state similar to napping\n\nAdult male dolphins, which generally travel in pairs, often swim slowly side by side as they sleep. Females and young travel in larger pods. They may rest in the same general area, or companionable animals may pair for sleeping while swimming.\n\nWhile sleeping, the bottlenose dolphin shuts down only half of its brain, along with the opposite eye. The other half of the brain stays awake at a low level of alertness. This attentive side is used to watch for predators, obstacles and other animals. It also signals when to rise to the surface for a fresh breath of air. After approximately two hours, the animal will reverse this process, resting the active side of the brain and awaking the rested half. This pattern is often called cat-napping.
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You could try to provide environmental conditions similar to the ones in their natural habitat. Some fish are nocturnal and will be sleep-like in the presence of daylight, or viceversa. \nThere are also anaesthetics for fish, such as clover oil or MS-222. You should consult an animal physiologist before administering them, though.
83895
No,dolphins are not nocturnal.
397272
There are a lot of urban myths, this could be one. Still it is possible that a social animal like dolphins may try to help a human in distress. I suspect that they would easily detect our panic with their hearing. I doubt that it is totally instinctive since there is no apparent value to the dolphin. It could be play. Have you seen the footage of killer whales tossing seal cubs around as toys? Unfortunately there are records of dolphin pods fighting each other.
164877
they are mammals so they breathe air
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Whales are fat primarily because they eat massive amounts of  food that contains a lot of fat.\n\nAnd before anybody tells you that whales aren't fat, let me assure you that they are. A wild whale has about the same body fat as a fattened domestic pig. \n\nWhales need that fat because it streamlines their body, making it easier to swim, and to keep them warm in the cold waters in which they live.\n\nFemale whales need a lot of fat because they often go without eating for 3 months or more when they give birth as they swim to warm water breeding grounds where there is no food.
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some whales mate on their sides at the surface and roll over periodically; as far as breathing goes, even if they werent at the surface, they can hold their breaths for pretty long periods of time. certain whales have also been known to mate in groups, but im not personally sure how this works..\n\nanyway, most whale sex is underwater actually and pretty quick, and no they dont get stuck.\n\nif you are really looking for details, here is a good quick site:\nhttp://whale.wheelock.edu/archives/ask00/0221.html
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fish usually sleep on the bottom of the tank and giraffes only sleep 30 min a day thats all i know
1010312
yes.\n\nthey are mammals and do not breathe underwater.\n\nthey take in air at the surface, so it does not matter what type of water they live in.
891350
People die in all sorts of places. Some of them go to certain places because they know there gonna die... so what's the difference for an animal... It's the Dolphins' natural instinct to go to land when they are ill or on the verge on dying.... It's not very often they wash up on shore by accident... maybe babies but most of the time its to die.
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Whales do not have body hair. In utero they have sparse hairs that are lost further along in development. they do not have any actual hair on their body, not even little ones that we cannot see with the naked eye.Hairs along the body would severely interfere with their hydrodynamics and increase drag, thus reducing their efficiency in the water, so it would not behoove them to maintain hairs.
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Unlike marine mammals such as whales and dolphins with lungs that store oxygen from the surface air, fishes have gills. Gills are a series of membranes located on each side of the fish that function as respiratory organs. As water passes over this system of extremely fine gill membranes, the fishes absorb the oxygen from the water. The gills contain a network of fine blood vessels (capillaries) that take up the oxygen and diffuse it through the membranes. When fishes are taken out of water, they suffocate, because their gills collapse and they are unable to absorb oxygen.In many ways, the interior of the fish resembles that of many other animals. The digestive, circulatory, and nervous systems are very similar to those of other vertebrates. However, what really makes a fish different from other animals is its respiratory system. \n\n\n\nA fish’s respiratory system is determined primarily by the fact that it spends its entire life in water. Unlike the marine mammals such as whales, a fish has evolved in such a way as to not require frequent trips to the surface to breathe air. Fish have developed gills, on which they rely for the oxygen necessary for a fish’s limited metabolism. \n\nMany animals have gills at some stage of their life (even humans have them at an early stage of their development in the womb), but fish retained these gills and they are still a functional part of their anatomy. Fish use their gills to extract oxygen from their watery environment. The process starts with the fish’s mouth, which is how the fish takes in water. When a fish opens and closes its mouth, it is actually pumping water back through the gills and is thus breathing. Most fish have an effective pumping system that involves the mouth and the outer cover of the gills, called the operculum. When the fish’s mouth opens, the operculum closes, drawing water into the fish’s mouth. When the fish closes its mouth, the operculum opens, allowing fresh water to cross the gills. Other fish have a less effective pumping system, requiring them to swim constantly to keep fresh, oxygenated water flowing over the gills. These types of fish, such as tuna, generally swim with their mouths partly open. Incidentally, while many fish have nostrils, the nostrils are used only for a sense of smell, and play no part in respiration. \n\nOnce through the mouth, the water continues past structures called gill rakers. The gill rakers are essentially a filter system for the gills, straining the water to sift out floating food particles or foreign material. After passing through the gill rakers, the water continues through the gill arches and actually passes over the gills, which are suspended between the mouth cavity and the operculum. Each gill is made of two rows of gill filaments, which are extremely thin membranes sticking out into the water flow. Each of the gill filaments is composed of rows upon rows of lamellae, which are thin, disc-like membranes loaded with a capillary network. The water flows across the lamellae, and oxygen and carbon dioxide are exchanged directly across the capillary membrane. The capillaries are situated to take best advantage of the water flow; fish can actually extract up to 85% of available oxygen out of the water. Since water contains only 2-5% of the available oxygen that air at sea level does, such a high efficiency is extremely important. \n\nFrom the gills, the deoxygenated water passes out the operculum, and the oxygenated blood joins the circulatory system. Despite the efficiency, some fish require more oxygen than others. This helps to explain why some fish thrive in specific habitats. For example, trout prefer northern streams because the cool water of the streams tends to retain dissolved oxygen, and the active trout need the extra oxygen. Carp, on the other hand, are sluggish and do not need as much oxygen, which is why carp can thrive in warm, relatively stagnant ponds, such as ornamental ponds. Goldfish, unlike most f
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It was once believed that all sharks had to swim constantly in order to breathe and could not sleep for more than a few minutes at a time. Oxygen-rich water flows through the gills during movement allowing the shark to breathe. While some species of sharks do need to swim constantly, this is not true for all sharks. Some sharks such as the nurse shark have spiracles that force water across their gills allowing for stationary rest. Sharks do not sleep like humans do, but instead have active and restful periods.\nhttp://www.flmnh.ufl.edu/fish/sharks/nsrc/Basics.htm#sleep\n\nIt is unclear how sharks sleep. Some sharks can lie on the bottom while actively pumping water over their gills, but their eyes remain open and actively follow divers. The spiny dogfish's spinal cord, rather than its brain, coordinates swimming, so it is possible for a spiny dogfish to continue to swim while sleeping. It is also possible that a shark can sleep with only parts of its brain in a manner similar to dolphins.\nhttp://en.wikipedia.org/wiki/Sharks#Shark_sleep\n\nIt depends what you mean by sleep. When humans sleep we are not conscious of what is going on around us, we kind of shut-down for a while and are not able to walk around unless we happen to be sleep-walking. Sharks rest in a different way. They can rest part of their brain while still swimming along, semi-aware of what's around them. Sharks that are able to stop swimming will settle on the seabed, and species like the British Bullhuss shark actually close their eyes - so they appear to sleep like we do. In our aquarium I have seen two Sandtiger sharks bump into each other nose-to-nose. They were so startled, they both took off at great speed in opposite directions. This suggested to me that they were dozing on the move and not paying full attention to where they were going, but I have never seen them bump into the sides of the tank when snoozing, so they normally seem to have an idea of where they are. A lot of research has been done on sleep in humans, and many mysteries still surround sleep and its importance to healthy living, but conducting similar research on sharks is almost impossible for practical reasons, we have a lot to learn about sleep and its purpose in fish and other animals.\nhttp://www.national-aquarium.co.uk/databases/FAQsLibrary/index.asp?FAQCategoryID=&FAQID=767&Sear
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They breathe air because as mammals, they have lungs. That's a constraint imposed by their evolutionary history; no mammal has "re-evolved" gills or other respiratory surfaces.\n \nOn the other hand, living in salt water has allowed them to develop huge bodies with little skeletal support. On land, where gravity is not counteracted by buoyancy, the sheer pressure exerted by the weight of their own bodies makes their bodies collapse. In addition, their skin dehydrates rapidly when exposed to the air. Thus, adaptation to a given environment always constrains survival in different environments. Evolutionary paths are like that.
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Both dolphins and porpoises are mammals. Even though they both live in the ocean, they are not fish. They do not have breathing gills. They have lungs and breathe air. Both also give birth to live young and nurse those young. A mammal is also characterized by having the presence of hair: when dolphins and porpoises are small, there are small hair follicles. \n\nDolphins and porpoises belong to the same scientific order, Cetacea. This order includes all whales, even the great whales, to which both dolphins and porpoises are related. All cetaceans are completely aquatic mammals, have a streamlined body, a tail fluke, and a blowhole (which is what these air-breathing animals use to breathe). The dolphins and porpoises are also classified in the scientific suborder, Odontoceti, which are the toothed whales. All odontocetes also have the ability to echolocate, the ability to detect objects in their underwater environment using the echoes of a sound, much like sonar. \n\nPorpoises and dolphins are classified into two different families. The porpoises are in the family Phocoenidae and the dolphins are in the family Delphinidae. When separated at the family level, dolphins and porpoises are as physically different as cats and dogs.
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Yes but they breathe very slowly, only a few breaths per hour, I think. Also they breath from the underside of their bodies, near their rears. That's why they can burrow their heads.
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When human and animal is lying down, all muscles are relaxed, so brain is relaxed too, and sleep is more comfortable, but some mamalians, for example horse can sleep standing, because it's body is adapted.