Dolphins can stay up to 15 minutes under water, but they cannot breath under the water.
Dolphins use a technique called echolocation to find food and navigate.
Dolphins live in groups formed by 10 to 12 individuals.
There are 36 different kinds of ocean dolphins and 5 species of river dolphins.
The largest dolphin is the “killer whale” (also known as Orca).
The most known dolphin is the “ bottlenose dolphin”.
Dolphins are warm-blooded.
Dolphins communicate through sounds and whistles.
Dolphins eat fish and squid.
Dolphins may live in the ocean, but they’re mammals that are fully adapted to live in water.
There are a number of adaptations that dolphins developed during their creation living in water instead of on land. For instance, dolphins and other cetaceans have no hair whatsoever, with the exception of a few follicles on their lower jaws and snouts.
Probably one of the most important difference between land mammals and dolphins is the way they vocalize.
While most mammals have a larynx or a similar structure that allows them to vocalize using throat vibrations and exhaled air. Dolphins and other cetaceans are no different; but they’re specially adapted to make extremely high-pitched sounds used for echolocation as well as more human-pitched sounds used for ordinary communication with others in their pod.
In addition, dolphins have extremely sharp hearing, and much better vision than one might expect of an animal that uses echolocation as its primary means of sensing the world. Dolphins can see limited colors, and even have limited binocular vision like a primate. They do not possess much of a sense of smell, however.
One of the most interesting differences between cetaceans and fish is in their swimming method. Fish swim by wiggling left and right, and if you watch crocodiles and snakes you’ll see the same motion. But because dolphins were descended from mammals with a quite different skeletal structure, they use up and down strokes to swim.
Today you can still see some of the remnants of terrestrial mammals in the dolphin’s skeletal structure. For instance, they have forelimbs, but they’re adapted into flippers with shortened arm bones and no fingers. Hind limbs can sometimes be found as vestigial skeletal remains, much like tails can still be found vestigially on some humans. Most cetaceans, including dolphins, still have a pelvis, which is entirely absent from fish.
Unlike other mammals, a dolphin’s hind quarters are much, much more developed than its front musculature; the flippers are only to steer, while the tail provides most of the force of motion. Dolphins have also developed horizontal flukes on their tail to make propulsion more efficient, and they’ve developed a dorsal fin just like fish. External parts that get in the way of a dolphin’s streamlined shape, like the genitalia or the ears, have been entirely lost, turning into internal organs instead.
Dolphins, like other mammals, breathe air instead of water, and thus use lungs instead of gills. A dolphin that cannot surface also cannot breathe, and thus will drown; this is why dolphins caught in fishing nets are given such a poor chance of survival. Unlike most fish, dolphins are very much creatures of the surface of the ocean.
Like whales and other cetaceans, dolphins respire through a blowhole in the tops of their heads, breathing in air when they break the surface of the water. Unlike humans, dolphins do not breathe reflexively; instead, they have to remember to breathe. An unconscious dolphin is likely to be a dead dolphin. Though when actively swimming they must breathe fairly often, dolphins can hold their breath for fifteen minutes or more.
Dolphin Sound Diversity
Pods of dolphins in the English Channel stay on their own side – the French-water dolphins on the France side and the English-water dolphins on the England side – even though they are of exactly the same species and might be expected to mingle more. Some researchers say that this indicates not just language, but that two groups have developed distinct language that can’t be understood by the others.
Whether you buy that or not, there is a lot of research on dolphin vocabulary that indicates they communicate with at least as much sophistication as the higher apes. They have a vocabulary of danger sounds, food sounds, and seeking sounds, and sometimes put these sounds together in a reasonably complex fashion. There is also evidence that they may greet one another by name; specific sounds are only uttered when meeting certain dolphins. Dolphins and Man-Made Sonar
dolphin echolocation abilities are much superior to those of any man-made device. For this reason, the US Navy have been studying them for years in order to improve their own sonar. What they’ve found has been surprising.
Dolphin Language and Communication
In the larynx, dolphins can produce high-pitched whistles and squeals which can rapidly change pitch. Whistles are single tones, with no vibrations that make them sound like buzzes. As far as scientists can tell, the whistles are a form of communication with other dolphins, and squeals are used to express alarm or sexual excitement.
Like most other animals, dolphins do have communication. Their squeals and whistles communicate emotional states and, often, the presence of danger and food in the area. They may also help them coordinate “herding” processes. Dolphin females often act as “midwives” to new mothers, and every dolphin in the pod cares for the others.
Echolocation is a technique used by some animals to detect other animals, food and obstacles.
As implied by its name, this technique uses the echo, produced by a sound emitted by the animals with this capability, to locate such objects.
Dolphin Echolocation. Dolphins make a sound that travels quickly through water. The sound is bounced back and the information decoded in the Dolphin Melon.
The sound travels in the form of waves and when it is bounced back by solid objects either in water or air, it is then detected by the dolphin. This bouncing is called “echo” and it is the same as the voice echo we hear in caves, but at a much precise level.
In the case of dolphins, they emit a a beam of clicking sounds forward in the direction fo their head and receive the echo from this sounds in the lower jaw.
This technique is used by humans in radars or sonars where some kind of wave is emitted and the bounced back wave is detected and processed.
Dolphin Sophisticated Senses
Dolphins have surprisingly good vision, able to see a fish in a trainer’s hand well enough to snatch it from the hand without harming the trainer. They have binocular vision to a certain degree, like a human does. They don’t have great color vision, though; it’s comparable to a severely color-blind person. And why would they need it when they live most of their lives well underwater?
Some dolphin behaviors associated with their vision indicate high specialization of the two sides of the brain, which is associated with intelligence. For instance, dolphins tend to swim in a counterclockwise direction in tanks. And when presented with new visual stimulation, like new people, they tend to look at them with their right eyes.
Whaling ships have long known how sensitive the hearing of any cetacean is. They always went as silent as they could when stalking whales; any sound in the water could lead to loss of their catch. Dolphins are no different from whales in this respect. Though their echolocation sounds don’t seem all that loud to a human, they can hear the bounced-back sounds from tiny objects as far off as 120 yards.
Dolphins may have two hearing sense organs. The melon of a dolphin (you can see this – it’s the big off-center lump on their foreheads) focuses their echolocation sounds, and may have just as much to do with collecting the sounds bounced back from echolocated objects. They do also have regular ears, and their ability to hear is among the best in the mammalian world.
Some other cool facts and types of dolphins are: