Dolphins, along with whales are mammals, and are supposed by researchers and historians to be the remnants of land mammals, which entered the water to live several million years ago.
Dolphins have residual legs near where the tail meets the body as you can see in this picture of a dolphin.
Dolphins are very fast swimmers due mostly to their bodies which are built in a streamlined way that help the water to flow over them easily.
They are usually grey with a lighter under side and have a darker coloration on their backs. Sometimes they also have patchy areas of other colors as well.
Dolphins have an organ that they use to locate things by echo, a sort of sonar device built into them called a melon.
They have very large brains and a cortex which is structure in a very elaborate manner, and so are advanced in intellect in many ways.
Dolphins do not have hair or fur like other mammals.
Both male and female dolphins have their reproductive organs on the underside of the body. Males have two areas, while females have just one slit on the underside; however she does have to more which house her milk producing glands, the mammaries.
Dolphins reproduce belly to belly, which is very uncommon in sea creatures. Dolphins are one of only a handful of creatures aside from humans which will mate when they are unable to reproduce and will sometimes display sexual advances toward people.
Dolphins have extremely good eyesight, both above and below the water, and they also have a highly advanced sense of hearing due to an arrangement of their teeth, which seems to work as a receiving device for incoming sound.
Dolphins are thought of as one of the smartest of all mammals. They have been trained to do highly involved work for governments and individuals and have carried out complex tasks with little or no difficulty.
Dolphins in the wild live in groups which are called schools or pods. These pods contain up to twelve or more dolphins, usually a family unit.. Dolphins will also go into large meetings or meetups that can contain upwards of a thousand animals which is termed a super pod.
Dolphins do communicate with each other and very often seem to talk to each other using clicks and whistles.
Like humans they will become very attached to each other, forming friendships which will cause them to grieve when the other animal or child is killed.
Dolphins have been with the world for a very long time, and pictures of them are seen throughout history as far back as Roman times.
They are also a large part of Greek myth and history.
Reportedly they have many times protected humans from shark attacks, will swim repeatedly in circles around them to prevent the shark from approaching, and will approach and playfully interact with people even when they have not come in contact with humans before.
Sadly, despite us having studied dolphins and their behavior for many years there is still so much we don’t know about them.
Find out more about the Dolphins over at Wikipedia »