The simple answer is no, dolphins don’t have gills.
In fact gills are actually a common characteristic of fish, sharks(a variation of fish) anda variety of amphibious creaturesthat enables them topull oxygen directly out of the water so that they can breathe in an aquatic environment without needing to rise to the surface of the water.
Depending on the species some amphibians can breathe both underwater and on the surface, however most fish and sharks can only breathe underwater and unlike mammals fish would actually suffocate above the surface of the water.
In contrast to fish and sharks dolphins are marine mammals and must come to the surface in order to breathe.
Dolphins are equipped with lungs (like humans and land animals) not gills and would drown if they tried to breathe underwater just as a human would drown if they tried to inhale while submergedunderwater.
In order to breathe dolphins swim to the surface and inhale oxygen through their blowhole, which can be found on the top of their head.
One interesting characteristic that separates dolphins from land based mammals is that unlike humans and land animalsdolphins are incapable of breathing through their mouth because their trachea and air passage are not connected.
This serves several purposes for dolphins.
First of all having a separate trachea and esophagusallowsdolphins to surface partially above the water while only exposing their blowhole, which makes it easier to breathe and allows them to rest without having to constantly monitor whether or not their head is above the surface.
If a human or land animal were to obtain oxygen they would have to lift their head completely out of the water which would take additional energy and require the animal to orient their entire body into a position where they can successfully breathe above the water.
A dolphin on the other hand can simply log around at the surface using little or no energy to acquire its oxygen.
Secondly, by having a separate breathing system dolphins are able to hunt for and consume fish and various otherprey while under the water without the fear of drowning.
They don’t have to be concerned with opening up their lungs and accidentally filling them with water every time they hunt for fish and other prey.
Third, having a blowhole on the top of their head allows them to maintain good visual awareness of objects, prey and predators around them as they do not have to be distracted with lifting their head out of the water.
When it comes to breathing some dolphin species such as the killer whale may be seen spouting water from its blowhole when it rises to the surface of the water.
Whenthis occurs the dolphinis simply blowing the water that has collected around its blowhole away.
It isn’t water that has been ingested through the mouth, lungsor blowhole as most people assume, its just water surrounding the outside of the blowhole that has been powerfully forced away when the dolphin exhales.
Before the dolphin dives back underwater it takes in a fast deep breath and closes the sphincter muscles around its blowhole to prevent water from getting in so that it can hunt and travel underwater without drowning.
The amount of time a dolphin can hold its breath for varies from one species to the next with estimates of 3 – 15 minutes being considered average for certain species.
In order for dolphins to stay submerged for extended periods of time certain unnecessary biological functions shut down to conserve energy and as much as 90% of the air a dolphin inhales is considered usable oxygen which is several times higher than that of a human and some land mammals.
Living in the ocean for millions of years has allowed dolphins to become extremely efficient at minimizing energy usage and maximizing the amount of quality air they inhale.
Will dolphins ever develop gills?
It is extremely unlikely that dolphins will ever evolve gills; at least not for several million years.
In fact it took the ancestors of dolphins millions of years to evolve from land dwelling animals into the marine mammals we now know today.
Dolphins belong to the cetacean family which also includes all species ofporpoiseand whaleand is comprised of over 80 different marine mammals.
All of these marine mammals are split into two suborders which are referred to as the baleen whale and toothed whale suborders based on their characteristics.
All species of dolphin belong to the toothed whale suborder as they possess teeth and are equipped with echolocation.
In regards to why it is unlikely that dolphins will ever develop gills is because evolution isan extremely slow process that occurs over millions of years and while dolphins have evolved from land animals to marine mammals they still share many of the same characteristics as other mammals such as the need to breathe air, being warm-blooded animals, giving birth to children, having hair (some species have hair at birth which falls off shortly after they are born) and producing milk.
Although gillsare not a common feature of marine mammals they are a common feature of fish, sharks and several other cold-blooded animals.
In order for a dolphin todevelop gillsits entire respiratory and lung systems would have to evolve.
It would also have to make evolutionary sense for dolphins to develop gills.
Fish can be found thousands of miles below the surface of the water andsome speciesnever come to the surface of the water throughout their entire lives, and while dolphin are able to dive to fairly deep they always rely on their ability to come back to the surface and thus are unlikelyto dive deep enough to the point where they wouldrequiregills for survival.
Aside from living at deeper depths fish are also cold-blooded which means they’re able tosurvive in extremely deep oceans that possess very low temperatures; even in areas that do not possessany light.
Because fish are small in size and do not possess body fat their cold-blooded physiology allows them to survive at these depths despite not being able to develop their own internal heat and they can survive off of fewer calories than a warm-blooded animal that needs to keep itself warm.
If a dolphin were to develop gills it would also have to develop a biological system that would allow them to maintain their oxygen supply and body heat at extreme low depths for an indefinite amount of time.
In other words dolphins would likely have to become cold-blooded animals to survive at these depths or become really efficient at burning the calories they consume for body heat and to support other biological systems.
Unlessevolution requires dolphins to survive at these extreme depths for huge amounts of timein order to survivethe likelihood of the dolphins ever developing gills will remain extremely low.
Dolphins are marine mammals not fish and like humans these marine mammals would drown if water entered into their lungs.
Unlike fish they cannot breathe underwater so they must come to the surface to get air.
In addition to helping them get air their blowhole also helps them survive in the ocean by minimizing the energy it takes to breathe near the surface, allowing them to maintain awareness of their surroundings and minimizing the chances of taking water into their lungs when consuming food underwater.
Dolphins have also perfected their ability to inhale quality oxygen and use it effectively in order to stay submerged underwater for extended periods of time, search for food, navigate the ocean or escape an attack from a predator.
Do whales and dolphins have gills? ›
Whales and dolphins are mammals and breathe air into their lungs, just like we do. They cannot breathe underwater like fish can as they do not have gills. They breathe through nostrils, called a blowhole, located right on top of their heads.How long can dolphins hold breath? ›
Dolphins have been known to hold their breath for up to 20 minutes underwater, but the regular maximum time for submersion is considered to be 10 minutes.Which fish has no gills? ›
The two aquatic animals which have no gills are dolphins and whales. These animals must come to the surface in order to breathe as they cannot breathe underwater without gills.How do dolphins sleep if they can breathe underwater? ›
When sleeping, dolphins often rest motionless at the surface of the water, breathing regularly or they may swim very slowly and steadily, close to the surface. In shallow water, dolphins sometimes sleep on the seabed rising regularly to the surface to breath.Are dolphins lungs or gills? ›
Even though they live in the ocean all of the time, dolphins are mammals, not fish. Like every mammal, dolphins are warm blooded. Unlike fish, who breathe through gills, dolphins breathe air using lungs. Dolphins must make frequent trips to the surface of the water to catch a breath.Why didn't dolphins develop gills? ›
In regards to why it is unlikely that dolphins will ever develop gills is because evolution is an extremely slow process that occurs over millions of years and while dolphins have evolved from land animals to marine mammals they still share many of the same characteristics as other mammals such as the need to breathe ...Why can't dolphins survive on land? ›
Dolphins live exclusively in the ocean because they have not developed the necessary muscles to sustain themselves on land.How long does a dolphin sleep? ›
Dolphins need about eight hours of sleep a day, but, unlike us, their brain sleeps in shifts. The right half gets four hours of sleep and the left half also gets four hours of sleep, just at different times. The awake half of of a dolphin's brain not only helps keeps the dolphin breathing.What animal can hold breath for 7 hours? ›
Although they aren't mammals, sea turtles hold the record for the animal that can hold its breath the longest underwater. When resting, sea turtles can stay underwater for days. On average, sea turtles can hold their breath for 4 – 7 hours.Which animal doesn't need oxygen to survive? ›
In a study published Monday in the Proceedings of the National Academy of Sciences , researchers have now identified the first animal that doesn't use oxygen to breathe: Henneguya salminicola, an 8-millimeter white parasite that infects the flesh of Chinook salmon.
Which animal Cannot breathe underwater? ›
The two aquatic animals which have no gills are dolphins and whales. These animals must come to the surface in order to breathe as they cannot breathe underwater without gills.How long can a dolphin survive out of water? ›
Not only do they recognize their need to come up for air, but they also manipulate their circulatory systems when needed to extend their time below the surface. On average, dolphins can hold their breath for a total of between 8 to 10 minutes.What are animals that don't sleep? ›
Animals that don't need sleep (bullfrogs and dolphins) Animals that don't need rebound sleep after using up all their energy (bees) Animals that show harmful side effects from sleep deprivation (humans)Can dolphins survive out of water? ›
A dolphin can live out of water for hours IF it is kept wet and cool. One of the biggest dangers to a dolphin being out of water is their inability to regulate their body temperature. We will explain how dolphins regulate their blood temperature and the risk this poses to dolphins out of the water too long.Do dolphins have nipples? ›
Cetaceans nurse their young just like land mammals do. Unlike the exposed nipples of humans and our closer kin, the mammary glands of dolphins and porpoises are concealed inside of abdominal slits. The mother squirts the milk into the calf's mouth to account for the difficulty of underwater suckling.What animal can hold its breath the longest? ›
The longest ever recorded dive by a whale was made by a Cuvier's beaked whale. It lasted 222 minutes and broke the record for diving mammals. Other whales can also hold their breath for a very long time. A sperm whale can spend around 90 minutes hunting underwater before it has to come back to the surface to breathe.Do alligators have gills? ›
As reptiles, alligators have extremely different lungs from ours, like other reptiles such as lizards and snakes. But unlike fish, they lack gills. They can't breathe underwater, so they only show off their excellent breath-holding abilities when they submerge themselves for extended lengths of time.Why do sharks not mess with dolphins? ›
To compliment dolphins' superior intelligence is their incredible speed. They can swim faster than most shark species making them an elusive meal not worth the chase.Why can't dolphins go in freshwater? ›
When they go into fresh water, it starts peeling off. When it peels off, bacteria and fungi invade it. Then it eventually dies," Solangi said. Scientists said when a dolphin is first spotted in freshwater, ideally they could help return the animal to its proper habitat, but that's not an option.Why are there no sharks when there are dolphins? ›
This myth is often associated with a shark safety tip: “If you see dolphins, it's safe to swim there because their presence scares away sharks.” This is simply not correct. In fact, sharks and dolphins are often found near each other for a simple reason—they eat the same food, and both go where the food is.
Why shouldn't you push a dolphin back into the water? ›
DON'T push the animal back out to sea!
Returning animals to sea delays examination and treatment and often results in the animal re-stranding in worse condition.
Dolphins saving people
No one knows why, but dolphins have been saving people for thousands of years. Dating back to Ancient Greece, there are dozens of claims of dolphins rescuing people from sharks, helping drowning sailors, and guiding boats through rough waters.
While the majority of dolphins in the U.S. are bred in captivity, they are not domesticated animals. Pushing people into deeper water, head-jerking, and biting causing broken bones, skin abrasions and other injuries have all been reported with direct contact interactions with dolphins.How smart are dolphins really? ›
Research shows that dolphins mirror self-recognition, cultural learning, comprehension of symbol-based communication systems, and an understanding of abstract concepts — comparable to chimpanzees and other great apes.Do dolphins have predators? ›
In the United States, dolphins are safeguarded by the U.S. Marine Mammal Protection Act. Bottlenose dolphins are top ocean predators with few predators of their own, although they sometimes become prey for sharks and orcas.How many days do dolphins live? ›
A brief summary of what I found out:
The average survival time in captivity for all bottlenose dolphin individuals who lived more than one year is 12 years, 9 months and 8 days – much lower than the wild where they live to between 30 and 50 years.
Koalas are the longest sleeping-mammals, about 20–22 hours a day.How long does a hippo hold its breath? ›
When totally submerged, the ears and nostrils shut tight to keep the water out, and hippos can hold their breath for five minutes. Hippos often nap in the water during the daytime. A subconscious reflex allows them to push themselves to the surface to breathe without waking up so they can sleep without drowning.Are there any whales with gills? ›
No, whales don't have gills; instead they are born with blowholes. Gills are actually a common feature of fish and many other amphibious species, however they are not present in whales or any of the cetacean species (whales, dolphin & porpoises) for that matter.Which animal do not have gills? ›
Animals that live inside water but do not possess gills include whales and dolphins. These animals breathe with the help of blowholes that are located in the upper regions of their heads.
Is a whale a fish and it breathes through gills? ›
Final answer: Whales and dolphins like fishes live in water. But they do not have gills. They breathe through blowholes.How long can a whale hold its breath? ›
The longest ever recorded dive by a whale was made by a Cuvier's beaked whale. It lasted 222 minutes and broke the record for diving mammals. Other whales can also hold their breath for a very long time. A sperm whale can spend around 90 minutes hunting underwater before it has to come back to the surface to breathe.Do whales have nipples? ›
Whales and dolphins do not have external nipples, instead their nipples are enclosed within mammary slits. Upon stimulation of the calves nudging, the nipple is exposed and the calf positions itself such that the nipple is at the gape of the calf's jaw for feeding.Do whales sleep underwater? ›
If asked, do whales sleep underwater? The answer is simple, YES they do. Their bodies shut down but only half of their mind stays at rest so that they conscientiously remember to breathe. Breathing near the surface where whales sleep allows them to breathe more conscientiously, meaning each and every breath counts.What animal has gills then lungs? ›
Lungfish have a unique respiratory system, having both gills and a lung. It is the only type of fish to have both organs, and there are only six known species around the world.Which animal can breathe through lungs? ›
How do amphibians breathe? Most amphibians breathe through lungs and their skin.What animals can breathe underwater without gills? ›
The two aquatic animals which have no gills are dolphins and whales.How do whales sleep if they can breathe underwater? ›
Their brains do not trigger a breathing response until the levels of CO2 are much higher than what humans can tolerate. These mechanisms, part of the marine mammal diving response, are adaptations to living in an aquatic environment and help during the process of sleeping.How long do whales sleep? ›
They cannot sleep for much longer than 30 minutes without risking lowering their body temperature due to inactivity. A very common assumption is that whales sleep with half of their brain 'shut off' and one eye closed.Does snake breathe through lungs? ›
I will confirm that snakes in fact breathe through their mouths and noses, and that they have nostrils similar to ours. Not only that, snakes also have a pair of lungs just like we do!