Dolphins are aquatic mammals. Dolphins are closely related to whales and porpoises. There are approximately forty species of dolphins, which are divided into 17 genera. Their sizes range from 1.2 meters and forty kilograms – like a Maui dolphin – to 9.5 meters and ten tons – like an orca. It lives in all seas of the world, especially in the shallower seas on the continental shelves. It is a carnivore that feeds on fish and squid.
Dolphins also have openings at the top of their heads that allow them to breathe outside the sea and water, and they are found in all kinds.
The dolphin is one of the types of whales with small teeth, and there are more than 40 different types of dolphins, and there are 6 types of them that can be called whales, including killer whales or pilot whales, Dolphins are not fish even though they live most of the time in the water, As it is considered a species of oceanic mammals, and this category is divided into two main families, which are as follows: South Asian river dolphins, and their scientific name is (Platanistidae). Iniidae dolphins, scientific name (Iniidae). Physical Appearance Dolphin The dolphin has a streamlined body shape and has breathing gills and layers of fat necessary for thermal insulation; Adapted to live in the aquatic environment, the dolphin has a tail that moves up and down while swimming with a movement similar to the movement of the legs, and this means that the movement of the dolphin’s tail differs from the movement of fish tails, which move sideways. Smell and olfactory nerves, as for the dolphin’s nose, it resembles a curved beak, and its nose is long and thin due to the shape of the long and prominent jaw bones. As for the jaw of the dolphin, it contains a large number of conical teeth, as their number in some species reaches 130 teeth in each jaw, and one of the most famous types of dolphin With prominent jaws are the following: The Atlantic humpback dolphin. Bottlenose dolphin. Tokoxi dolphin. Spinner dolphin. The anatomy of the front limbs of the dolphin is very similar to the anatomy of the forelimbs of the rest of the mammals in terms of function, but the front limbs of the dolphin are short and solid, and the pectoral fins are used to guide and adjust the speed of the dolphin during its swimming. Some types of dolphins have this dorsal fin, such as: dolphins of northern origin and whale dolphins of southern origin. The ears of the dolphin are in the form of small openings located behind their eyes and these openings are not connected to the middle ear, and some scientists believe that the sound is transmitted from the openings of the outer ear to the ear Central and internal through fatty fats located behind the lower jaw and through various bones within the bones of the skull. Where does the dolphin live? Dolphins live in oceans, seas, and rivers. Some species prefer to live in coastal areas and others live in deep waters far from the coast. Most dolphins prefer to live in temperate tropical regions. Because the dolphin is classified as a warm-blooded mammal, which makes its presence in such areas better for it to regulate its body temperature. There is one type of dolphin that lives in the Arctic and Antarctic, and it is the orca dolphin; They are dolphins of large size that are distinguished by their ability to adapt to extreme cold and frozen water, and it is indicated that there are river dolphins such as the Amazon dolphin and the South Asian dolphin that live in rivers and freshwater lakes, where there are aggregations of dolphins that live permanently in freshwater rivers, such as: Toxi dolphin , Guyana, and Iwadi. Dolphin mating and reproduction The age of sexual maturity of a dolphin varies according to the type of dolphin, its location, and its gender. For example, female dolphins reach puberty between the ages of 5-13 years, while the age of puberty for male dolphins ranges between 10 -14 years, and dolphins are polygamous beings, and mating usually occurs between dolphins throughout the year, and the mating rate increases in some areas in the spring and autumn seasons. The pregnancy period of a female dolphin ranges from 9-17 months, for example, the period The pregnancy of a female killer dolphin is up to 12 months, while the period of pregnancy of a female orca dolphin is up to 17 months, and after the female gives birth to a young dolphin, she pushes it to the surface of the water for the purpose of breathing, and young dolphins feed on mother’s milk for a period of up to two years, and a young dolphin can stay with his mother for a period A long period of 5 years. The dolphin diet is considered one of the active predators that depend on a wide variety of fish, squid, and marine crustaceans for its food. The consumption of food by a nursing female dolphin reaches approximately 8% of its weight, and the stomach of the dolphin is distinguished by being divided into several sections, which speeds up the digestion process. dolphin; As each species prefers certain types of fish as food for it, and where coastal dolphins prefer to eat fish and invertebrates in the bottoms, while marine dolphins eat fish and squid, and evidence indicates that marine dolphins dive to great depths in the sea up to 500 meters in order to obtain Their food. Communication between dolphins The social network of the dolphin is a complex network, as it includes a few young dolphins and their mothers, and the dolphins share a relationship with a larger group of dolphins that move simultaneously to hunt and obtain food, where one of the adult dolphins is responsible for organizing the movement The group to obtain their prey by taking turns swimming within the fish groups to be preyed upon. Dolphins depend on sound more than any other method in communicating with them, as the speed of sound transmission through water is faster than its transmission in the air, and scientists believe that each dolphin makes A vocal whistle of its own that represents a distinctive identifying identity, and the dolphin uses this whistle to know the members of the group around it and to know their whereabouts. moving towards a place