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A photo of Dolphins taken in Marineland, Niagara, Ontario, Canada by Fabian Roudra Baroi –

20 Best Facts about Dolphins

Dolphins are famous among people because they are graceful and beautiful creatures. Their incredible performance while jumping in the ocean and their friendly face have made people like dolphins. 

A dolphin is an aquatic mammal within the infraorder Cetacea. Dolphin species belong to the families Delphinidae {the oceanic dolphins}, Platanistidae {the Indian river dolphins), Iniidae {the New World river dolphins}, Pontoporiidae {the brackish dolphins}, and the extinct Lipotidae {baiji or Chinese river dolphin}. In the article are 20 best facts about dolphins.

1. Live in groups called pods

A photo of a dolphin by Fabian Roudra Baroi –

All Dolphins live in groups called pods. Dolphins are social animals at all stages of life and have remarkable behaviours. A speeding group of Dolphins is a sight to see.

They move in and out of the water at high speed. The function of this movement is not known but it is the fastest movement they are capable of.

Dolphins mostly feed on fish. When they chase fish, the fish go into a bait ball to self-protect. In return, the dolphins attack in a group and eat as many fish as they can.

2. The name dolphin comes from the ancient Greek Delphis

The name dolphin comes from the ancient Greek delphis meaning “with a womb” because it was first thought to be a fish with a womb. It is now known to be a mammal and quite intelligent one.

Dolphins breathe air. A dolphin’s nose is on top of its head so the dolphin can easily breathe on the surface of the water. The skin of the dolphin has no scales. It is soft and smooth however, it is very firm, due to how much muscle they have.

Dolphins use echolocation to find their food. Echolocation is a way that some animals use to determine the location of things, they emit sound waves and listen for the echo. They use the delay to determine the distance. It is kind of a biological sonar. The skin of a bottlenose dolphin is grey, smooth and rubbery.

3. Dolphins are caring and protective

A photo of a girl petting a secret garden dolphin by Noah Wulf –

The dolphins are always social, they can help each other fight off predators. Dolphins have fought off sharks in this way. They can kill large sharks by ramming them over and over again with their snouts and heads.

The dolphins look after the younger ones when the mothers need to leave the calves to hunt for food. The young need to breathe more often than the adults and the food may be in deeper waters.

Oceanic dolphins are marine animals living in the sea. They live in all the oceans. Three of the four species of river dolphins live in freshwater rivers. The La Plata dolphin lives in saltwater estuaries and the ocean.

4. They sleep in the water

Dolphins sleep in the water. There is danger from animals that eat dolphins. Dolphins sleep differently than a person. They have two sides of their brain that they use to sleep. One side sleeps while the other one stays awake. Dolphins do things while asleep.

Dolphins will keep one eye open to watch the animals that prey on them while they are asleep. Dolphins also swim in circles when they are sleeping to look around for danger and then get their nose out of the water to breathe. Dolphin groups or species have their way of sleeping. Pinnipeds, like seals, can sleep like dolphins.

5. Dolphins have extraordinary senses

The brain of a dolphin is like that of a human being in size and development. Dolphins have reasonable eyesight. They can watch a thing in the water and they can see colours too. They can also see in dark places.

A dolphin’s hearing is better than its sight. There are small holes behind the eyes and those are the ears of a dolphin. Dolphins can hear sound underwater and they can know the direction of the sound very well.

6. They play an important role in human life

Dolphins have long played role in human culture. They are common in Greek mythology and there are many coins from ancient Greece which feature a man or a boy or a deity riding on the back of a dolphin.

The Ancient Greeks welcomed dolphins; spotting dolphins riding in a ship’s wake was considered a good omen. In Hindu mythology, the Ganges River Dolphin is associated with Ganga, the deity of the Ganges river.

Dolphin meat is eaten in a few countries including Japan and Peru. Japan may be the best-known and most controversial example but eating dolphins is not that common.

Dolphin therapy is sometimes used for people with mental or physical handicaps. It involves contact with trained dolphins. It is not agreed whether this is any better than the usual treatments. Scientists continue to study Dolphin therapy.

7. Underwater noise pollution is a threat to dolphins

A photo of Dolphin anatomy – by WikipedianProlific

Loud sound bursts are scaring cetaceans and causing them to flee into the depths of the ocean. The noise is throwing their bodies out of balance and risking their health, amid growing concern over the impacts of anthropogenic noise pollution.

Underwater noise created by shipping can disrupt echolocation hence making it hard for the dolphins to find food and navigate underwater, while also drowning out their communication with each other, displacing them from habitats and in extreme cases causing physical harm including temporary hearing loss.

8. Empathic towards humans

Dolphins have lent humans a helping flipper on countless occasions. In 2007, pods of dolphins circled imperilled surfers for over thirty minutes to ward off aggressive great white sharks.

In 2000, a fourteen-year-old boy fell off a boat in the Adriatic sea and nearly drowned before being rescued by a friendly dolphin. The marine mammal swam up alongside the boy and pushed him back to the boat from which he had fallen, where the boy’s father promptly scooped him up.

Far from being merely a modern phenomenon, historical accounts show that dolphins have been saving humans for centuries. In the 1700s, a pod of dolphins helped rescue Vietnamese sailors when their boat was sunk by Chinese invaders.

9. Dolphins love following boats

While dolphins are known for their intelligence, they also have a strong sense of curiosity. This brings up the first reason why they follow boats. The motion of a boat, its sounds and the disturbance of water prompt dolphins to go check out the strange object in their habitat. They approach the boat and swim alongside it to study this fast-moving object and observe the people on board.

Not surprisingly, dolphins try to swim as fast as they can. When a dolphin swims in the wake of a boat, its body is carried along on the waves making them move even faster than usual. They burn less energy while achieving a higher speed. in a way, when dolphins follow boats, they are getting a free ride!

10. They use sounds and nonverbal gestures to communicate

A photo of a dolphin waiting to be fed by a warden after entertaining guests by Fabian Roudra Baroi –

Dolphins communicate with each other through a wide range of sounds and nonverbal gestures. As sound travels faster through water than through the air, dolphins rely primarily on noises to communicate with one another.

They whistle and click and emit loud broadband packets of sound called burst pulses to discipline their young and chase away sharks. Scientists believe that every bottlenose dolphin develops a distinctive high-pitched whistle called a signature whistle. The signature whistle appears to serve as a means of individual identification, much like a name.

Research also suggests that certain types of physical contact between dolphins may signify important nonverbal communication.

11. Dolphins are carnivores

Dolphins eat a wide variety of foods including fish, squid, octopus, crustaceans, cephalopods and other marine life. Smaller dolphins usually stick to a diet of fish and other small prey. Larger dolphins such as the killer whale eat larger things, like sea lions, seabirds, sharks and penguins.

Dolphins do have teeth, but most of them do not use them to chew their food and swallow it whole head first, so the scales on the food do not disturb their throat. They use their teeth to defend themselves and to grip objects. They have two stomachs: one for food storage and the other for digestion.

12. Dolphins live a long time

The life expectancy of dolphins varies, but the common bottlenose dolphin can live a whopping 20 to 50 years! To determine a dolphin’s age veterinarians can count the rings inside each tooth. Each growth ring indicates one year of life.

The most critical time for mortality is during the first two years of a dolphin’s life. This is when they are most susceptible to disease, predators and adverse climate conditions.

13. A Dolphin can swim more than 20MPH

Dolphins have been clocked at a speed of up to 25 miles per hour when they are in a hurry trying to get away from something. Their normal swim is about 7-8 miles per hour though.

To swim quickly dolphins use their tail or fluke to produce thrust to push them through the water. the flukes as wings to generate a lift force that pushes them forward.

The flukes are flexible and dolphins can control flexibility. As they swim faster, the fluke might become stiffer. Researchers are still trying to pinpoint how they control the flukes’ flexibility.

14. Dolphins do not have hair

Dolphins have a few sparse hair follicles but hairs that are present fall out before or quickly after birth. They do not have any sweat glands either.

The outer layer of their skin is the epidermis. The epidermis isis extremely thick and constantly flakes and peels, just like humans. The epidermis of a dolphin is 10 to 20 times thicker than the epidermis of other mammals.

Their outer layer of skin is quickly sloughed off and replaced, keeping their body smooth and ensuring that they can swim efficiently.

15. Dolphins hold their breath much longer than humans.

Most dolphins can stay underwater for as many as 8 to 10 minutes. Some species can even stay underwater for up to 15 minutes.

They breathe through the blowhole that gets covered by a muscular flap when they go underwater. This keeps any water from getting into their lungs. The composition of dolphins’ lungs is different from humans hence allowing them to hold their breath longer.

Dolphin lung contains alveoli, which are tiny air sacs. Most mammals only have one layer of oxygen-carrying capillaries but dolphins have two layers.

16. There are Forty- Three Different Species of Dolphins

Dolphins are not just the grey medium-sized sea mammals that you see in the movies. There are forty-three different species, six of which are found in freshwater.

The dolphin species come in a variety of fun colours like black, white, blueish and sometimes even punk. Their colour comes from their diet and environment. The best-known species of saltwater dolphin is called the bottlenose dolphin while the best-known species of freshwater dolphin is called the Amazon river Dolphin, a much larger and odd-looking species.

17. There are Dolphins in the Amazon River

The Amazon River dolphin is also known as the Boto and its well known for its pink skin but they also come in shades of grey. Their colour comes from a variety of different factors including their behaviour, how close their capillaries are to the surface, their diet and how much sunlight they are exposed to.

Their colour can increase when they get excited, in a similar way to humans’ blush. They are around nine feet long and weigh about four hundred pounds when they are fully grown making them one of the largest species of dolphin.

The Amazon River dolphins are also more agile than other species since the vertebrae in their necks are unfused allowing them to turn their heads full 180 degrees.

18. The largest species of Dolphin is the Orca

The Orca also known as the killer whale is a dolphin. The name references that it kills whales, not that it is a whale that kills. Known for their distinctive colouring of black and white, orcas grow up to six tons; that is twelve thousand pounds or around the size of a bus. They are between twenty-three and thirty-two feet in length.

While orcas prefer cold, coastal waters, they can be found anywhere between the polar regions and the equator. They live in pods of about forty and can be both residential or transient. The residential orcas prefer fish while the transient ones are more likely to go after larger prey.

19. Dolphins use tools

Evolution, hunters and gatherers turned to tools to better be able to find food and perform work in an easier approach. As humans were evolving, dolphins were as well in their way.

Dolphins use tools. They have been observed picking up sponges to protect their snouts while they forage for food at the bottom of the water. While scientists are still discovering all the ways dolphins interact with tools, they clearly use them for many different purposes.

20. Dolphin skin is vulnerable to environmental elements

Dolphin skin is very unique. It has a soft and smooth feel kind of like a slippery river rock. This softness comes from how quickly the skin cells can regenerate on the surface of the dolphin. They slough off their skin all of the time and can regenerate it in as little as two hours.

Since dolphin skin cells are so active, they also react to pollutants. In fact in Sarota, there is evidence that bottlenose dolphins are being exposed to chemical compounds from consumer products. These chemicals are known to cause cancer in humans.