* The dolphin is considered one of the marine mammals that are closely related to whales and porpoises, and there are nearly forty species of dolphin in 17 genera, which differ in their sizes, starting from 1.2 meters in length and 40 kilograms, up to 9.5 meters in length and 10 tons in weight, and these types  The various are scattered all over the world and most of them are in shallow seas of continental shelves. They are completely carnivorous and most of them depend on fish and squid in their diet.

 * The dolphin is characterized by a spindle body, which is adapted to swimming at high speeds, and the color of the dolphin despite its difference from one species to another, but dolphins can generally be described as having a gray color and the abdominal part of the body has a lighter color and sometimes there are spots, lines and distinctive inscriptions on the body.

 * The head of a dolphin contains a round member called [Melon], and it is an organ that is used to locate the location by means of echo, and the mouth of the dolphin in many species extends to form a distinctive mouth similar to a beak, and in some species the mouth is slightly curved to form something like a smile, and live hate types  Dolphins can be up to 250 years old

 * Dolphins breathe through the breathing hole as in cetaceans. The brain of dolphins is very large and complex, and differs in its composition from most other marine mammals, and dolphins do not have any hair except for some hairs on their beaks, except that they have hair follicles that may perform some sensory functions.  Dolphins genital in the lower part of the body and dolphins have sharp eyesight in or out of the water, as well as have sharp hearing, and they can hear sound vibrations ten times or more above the maximum human hearing, also the dolphin has a developed sense of touch and the dolphin lacks the sense of smell.

 * Dolphins are social animals, living in flocks of dozens of individuals, and they gather in places that contain abundant food, and more than one flock may mix with each other for a temporary period to form a great flock that may exceed 1,000 individuals at times.

 * Squid and fish are the staple food for many types of dolphin, and some dolphins such as the killer whale prefer to eat other marine mammals.

 * And playing is an important part of the life and culture of dolphins, where dolphins play with seaweed, and at times they harass other animals out of fun, such as sea birds and sea turtles, and also ride waves and jump off them, and may play and interact in a fun way with swimmers, and it has been observed that  Dolphins in captivity create rings from the air and play with them.

 * The dolphin sleeps with only half of its brain, and the other half remains fully conscious so that it can breathe and pay attention to predators and other threats, while in captivity the dolphin enters a full sleep and closes both its eyes and there is no response to external stimuli.