Dolphins are a species of mammals of the underwater world, belonging to the Delphinidae family.Dolphins are one of the few marine mammals that are known to have close contact with human beings. They are extremely social by nature and are seen to form small, close groups of their kind.Whales and dolphins have an amazing and distinctive type of sleep, which is known as unihemispheric sleep. During this sleeping pattern, the species do not go into a state of deep sleep, only one half of the brain is unconscious, while the other half is alert and awake. In this state, whales and dolphins sleep with one eye open. To keep breathing while sleeping, these species need to have control over their blowhole, which is skin voluntarily controlled by dolphins and whales. While they sleep or are at rest, one hemisphere of their brain remains at rest while the other hemisphere shows signs of being active and remains awake. The reason behind being in this half-waking condition is to remain alert for attack from predators. During this period, they are awake enough to swim and reach the surface in order to get oxygen. Dolphins and whales are capable of selectively using their organs, which helps them breathe underwater for a longer period of time and maintain their unihemispheric sleep pattern.If you like reading how a dolphin sleeps, check out and learn more about how do amphibians breathe? And how do animals hibernate?Dolphin Adaptation Of Sleeping In Aquatic EnvironmentAs we know, the unihemispheric sleep pattern of whales and dolphins lets them float through the entire time of their sleeping period. Even though half of the brain remains at rest, the species do not drown and remain in a stable sleeping position.Scientists suggest, most aquatic mammals are not known to drown since they do not inhale the water. On the other hand, scientists state they might face a situation of claustrophobia due to suffocation caused by insufficient amounts of air. During this time, the need for a crucial amount of air is triggered by the sensation on the skin, and the dolphin has to come up in order to breathe. After which, they can travel deeper and sleep until the next sensation of air is felt on the skin. This process enables whales and dolphins to remain beneath the water and sleep.Half Brain Sleeping Patterns Of A DolphinThe sleeping patterns of aquatic animals like whales and dolphins are quite amazing as they show the signs of unihemispheric sleep. During these periods, they can switch from one side of the brain to the other one in order to remain alert, this pattern of sleep is known as cat-napping.While sleeping, whales and dolphins will not reach a state of deep sleep entirely but will keep half of the brain asleep. When one part is sleeping, the other part is capable of swimming and keeping one eye open. During this time, the muscle movement of the body remains active, which helps them to generate heat and thrive in cold underwater temperatures. For example, the bottlenose dolphins remain at this position of rest in order to alert themselves and watch out for the sudden attacks of the predators like sharks and other animals. The attentive brain also provides a sign to the dolphins to reach up to the surface for breathing. The process of resting one side of the brain changes every two hours where the hemispheres are made active alternatively.Dolphins’ Sleeping DurationSince whales and dolphins sleep in a unihemispheric sleep pattern, the species sleep for a particular span of time.Whales and dolphins mostly sleep during the nighttime. Few of them are spotted to be fishing for fishes and other small animals coming towards the surface from underwater at night. They sleep for a few hours a day, although a bottlenose dolphin sleeps for around 33.4% of the entire day. They are noticed to be more active towards the late night or early morning. According to research findings, it is suggested that it is not known whether the species dream or even undergoes a state of very deep sleep.Duration Of Holding Breath By A Dolphin While AsleepMarine mammals are known to have voluntary control of their blowhole, which helps these species to remain underwater, sleep and hold their breath. This is due to the fact that they have bigger lungs than an average human. While they swim or when they sleep, they are able to breathe and exchange larger amounts of air compared to humans.Research suggests since the lungs are large in size, unlike humans, these species of dolphins have a larger amount of air to exchange during the processes of inhaling and exhaling. The blood cells of bottlenose dolphins, for example, carry comparatively more oxygen and thus, have the capability of holding carbon dioxide for longer periods. This enables the species to hold their breath while swimming. When the level of carbon dioxide is more than the threshold of average humans, the cell of the brains of a dolphin does not send any trigger to the body. An average dolphin breathes almost 4-5 times in a minute and can hold their breath for eight minutes while they are sleeping or resting. In case of suffocation, they will swim up to the surface to breathe.Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for how do dolphins sleep? Then why not take a look at how do birds find worms, or how do dolphins communicate?
Dolphins are a species of mammals of the underwater world, belonging to the Delphinidae family.
