They’re aquatic mammals
These creatures are part of a group of mammals that dwell in the ocean and other bodies of water, whether it's partially or completely. They're mammals because the females have mammary glands that they use to nurse their young with milk.
Their name means ‘fish with a womb’
The Greek word for dolphin is delphís. This word is related to the word delphus, that means 'womb'. This leads specialists to believe that the Engñish word 'dolphin' means 'fish with a womb' (remember that dolphins are mammals!).
Their stomach’s got two chambers
Have you ever heard of animals that have stomachs with several chambers, such as cattle and giraffes? Dolphins also have two chambers in their stomach (fundic and pyloric). They use one stomach as a food storage, and the other is the one they use for digestion.
There are about 40 species of dolphins
Amazing, right? Experts say that there are about 40 species of these beautiful mammals! Six species of dolphins are called 'whales', but don't let that fool you! The melon-headed whale, the killer whale (or orca) and the pygmy killer whale are among them!
They eat fish
Dolphins prefer to eat fish or squid, although those considered whales feed on larger mammals. As you may know, some whales hunt seals. Dolphins are not the apex predators (which means they're not exactly at the top of the food chain), but they're threatened by very few animals.
They’re very kind with other dolphins
Dolphins are known for their intelligent, but experts assure they're also very kind creatures. If one of them is injured, a dolphin will always try to help. Experts have also observed that this behavior appears when they see other animals in trouble.
They don’t chew their food
Have you seen a dolphin's teeth? They're huge and sharp, right? Well, they're not exactly for chewing their food because dolphins do not do that. They just swallow their food whole! What are the teeth for then? Keep reading and you'll find out!
Their skin is delicate
We're sure you've more than once thought of how it would be like to touch a dolphin's skin! Their skin is actually soft and delicate, which means they're prone to get injured. But don't worry! Their skin also heals really quickly!
They’re very intelligent
Dolphins are believed to be one of the smartest living creatures, as are other cetaceans like porpoises and whales. Dolphins are known for learning, teaching each other things, cooperating and scheming with each other, and they also show signs of being capable of grieving.
They prefer warm waters
It's true that some dolphins live in cold water, but the truth is that most of them prefer their water to be warm, thank you very much. However, their skin possesses a layer of fat that helps them keep warm in low temperatures.
Their ears are adapted to their environment
These creatures' ears are adapted to the environment they live in (the same can be said about other marine animals). Us humans receive sound through our outer, middle and inner ear. But dolphins receive sound through their throats, and then the sound waves go straight to their inner ear.
They sleep with only one brain hemisphere
Non-human sleep is such an interesting subject! When dolphins sleep, there's a hemisphere of their brain that stays awake and alert. This is useful for them in case there's a predator nearby. It's been noticed that dolphins in captivity don't share this with those that live in the wild.
Female dolphins mate once every couple of years
Dolphins are known for how rich and interesting their sexual life and sexual habits are. But did you know that female dolphins only mate every couple of years? Also, they're the only ones with the responsibility of raising the calves that they give birth to.
But male dolphins mate much more often
Male dolphins don't mate every couple of years. They do it multiple times a year with several different female dolphins. Also, as we've mentioned before, they're not really involved in raising their offspring.
The gestation period is different for some species
The gestation period for these animals varies from one species to the other. For some dolphins, the gestation period lasts 11 or 12 months, and in other cases, it lasts for over a year (17 months for an orca).
They’re playful creatures
Dolphins are playful creatures and they're so much fun to watch! Those that live in captivity often entertain themselves with rings, balls and other toys their trainers and caretakers give to them. They also enjoy playing with each other or with other animals.
Females give birth to a single calf
Female dolphins give birth to a single calf each time. Mother and baby are beautiful to watch when they interact and play with each other. Are interact and play with each other. Aren't they the most adorable thing you've seen?
They have ‘names’ for each other
Scientists and experts in dolphin behavior have found in their studies that dolphins have 'names' for each other. Dolphins often communicate by whistling, and it seems that each member of the group has got their own distinctive, particular whistle. That's how they 'call' each other individually.
They like to engage in non-reproductive sexual behavior
Dolphins are known for enjoying sex and engaging in it for reasons that have nothing to do with reproduction. Just like us humans, dolphins often have sex with each other because they like it and it feels good.
They have sharp teeth
Remember that we mentioned that dolphins do not chew their food? Then what are the sharp teeth for, then? Dolphins use their teeth to catch their prey, especially those fish that are fast moving.
They like to stay close to mommy
When dolphins give birth, the other is responsible for taking care of the calf, nursing it and teaching it how to survive. Bu dolphins then stay with their mother for a very long time, even when they're not babies anymore. Some stay with mommy until they're about eight years old.
They show each other affection
Don't you think it's adorable when dolphins play together and give each other a kiss? Well, dolphins are very affectionate creatures and they're not scared of showing the members of their group just how much they care!
They are born tail first
A calf is born tail first, which is a very rare thing for a mammal. As you may know, mammals are usually born head first (otherwise, it can be dangerous for both the mother and the baby some times). This is not the case with dolphins.
They teach their young to use tools
One of the reasons why experts believe dolphins are capable of having a culture just like us humans is that they create tools, know how to use them to make their lives easier, and they teach their young to use these tools.
They live up to 50 years
Dolphins have a long lifespan, as they can live up to half a century! But sadly this only applies to creatures living in captivity. The average lifespan for a dolphin that lives in the wild is 17 years.
They engage in sexual activities before they reach sexual maturity
Dolphins often engage in sexual activities long before they reach their sexual maturity. When this happens depends on the species, but experts agree that most of them become sexually active before that time comes.
They are fast swimmers
Dolphins are fast swimmers! Well, one would expect them to be, right? They spend all of their time in the water! The characteristics of their neck vertebrae is one of the things that make them such great swimmers because it gives them stability at high speed (among other benefits).
They make a variety of sounds
Dolphins are known for chirping and whistling, but they actually are capable of making a variety of sounds, like clicks and other vocalizations. If you look online for videos of dolphins clicking your day will get 1000 times better, we promise.
It’s believed that they are capable of abstract-thinking
Dolphins may also be capable of abstract-thinking, according to some studies. A research conducted by specialists show dolphins have self-awareness, which indicates they may have highly developed abstract-thinking and meta-cognitive reasoning.
They’re prone to certain diseases
Dolphins don't have many enemies out there in the sea (although it's known of larger species of dolphins feeding on smaller dolphins), but they are prone to suffer from parasites and certain diseases that could be mortal, such as infections.
They can communicate non-verbally
As we've mentioned before, dolphins communicate verbally with each other and they even give other dolphins 'names' (special whistling-sounds). They can also communicate non-verbally with their posture and with their touch.
Killer whales are actually dolphins!
Yes, this is true. Killer whales belong to the oceanic dolphin family! They are one of the largest species of dolphins, and they are known for feeding on other mammals.
They have their place in mythology
Dolphins have their place in human culture. In Greek mythology it was thought that dolphins helped humans. There are also several Greek art pieces that show dolphins, such as a fresco found in Crete that goes all the way back to 1600 BC.
They breathe through a blowhole
Cetaceans have a hole at the top of their heads, like you can see on the picture above. They use this whole to breathe air, and if we compare this to other mammals' respiratory system we could say that the blowhole is like a nostril.
They’re great divers
Some species of dolphins are great divers and are known for being able to dive to great depths. Did you know that some of them can even regulate their heart rate so they can conserve oxygen?
Their hair follicles are very useful
Wait, but what hair follicles are you talking about, some of you may be wondering. Dolphins don't have hair! Well, but they do have hair follicles, and they are useful to them because, according to some experts, they perform sensory functions. Awesome, right?
They see in fewer colors than most mammals
Dolphins don't have such a great sense of sight like other animals. Their eyesight is actually pretty poor. According to some studies, dolphin see less colors than other mammals. Also, their eyes are really small compared to the size of these creatures.
They have a tapetum lucidum
A tapetum lucidum is a layer of tissue that many vertebrae animals have in their eyes (for example, dolphins). It helps increase the amount of light available to the photoreceptors, hence giving these creatures better night vision (which can be great when your eyesight is not very good to begin with).
Female are called ‘cows’
Wait, what? Aren't cows supposed to be found in farms, surrounded by green grass? Aren't cows that mammals that we drink milk from? Well, female dolphins are called 'cows', and male dolphins are called 'bulls'. Also, their babies are also called 'calves', as is the case with the offspring of cattle.
They can’t smell a thing
Apparently, a dolphin's olfactory system is non-existent. Experts have found that these animals lack olfactory lobes, which means that they cannot smell a thing. Good for them that they don't have a sense of smell, with all that fish around!
There are several reasons why they leap above the water surface
You've probably seen videos of dolphins leaping above the water surface. They do this mainly because when they jump there's less friction in the air, and they save more energy (it's useful if they're travelling). They also do it when they get in a fight, or when they're just feeling playful.
They live in ‘pods’
Dolphins live in groups. These groups are called 'pods', and sometimes they're also called a 'school' of dolphins. Sometimes there are up to 12 dolphins in a pod, but the structure of these groups depends on the species.
Some species are endangered
Some species of dolphins are endangered and they could become extinct if we're not careful with what we do with the oceans and the environment. In Japan there are people that hunt dolphins for fun, a practice that should be stopped.
Some males have to go into exile after a fight
Dolphins often get into fight with each other, especially when two male dolphins want the same female. The more a male dolphin ages, the more he'll get into fights. Some even have to leave the pond and go into exile if they lose a fight with another pod member.
Sometimes they engage in sexual behaviors with other species
Specialists say that dolphins often engage in sexual activities with other species of dolphins. Did you know that sometimes the sexual contact between these animals is really aggressive? (yes, don't let them fool you with their cuteness).
They are featured in several coats of arms
As we've mentioned before, dolphins hold a special place in human culture. These creatures are in the coats of arms of Romania, Anguilla and Barbados. Isn't that an amazing fact? Look up these coats of arms, they're pretty awesome!
Those in captivity are often kept in theme parks
Dolphins that live in captivity are often found in theme parks, such as Sea World. There they are trained to perform tricks and they're part of shows for the families that visit the theme parks.
They’re friendly with people
Dolphins are friendly creatures (yes, even they sometimes they engage in aggressive behaviour with each other). They're kind and always want to help other dolphins and animals, and they're also very friendly with us humans.
They use something called ‘echolocation’
Dolphins can do something called 'echolocation'. This means that they can emit calls to the environment, and then they wait to listen to the echoes. Why do they do this? Because the echo helps them locate and identify objects.
Some species have an organ called ‘melon’
Some species of dolphins have an organ called 'melon', an adipose tissue that is found on their foreheads that helps dolphin with echolocation. The melon is actually just fat on their skulls.