Dolphins breathe through their nose and mouth. Like humans, they breathe out the air from their lungs first, and then breathe fresh air through their nose and mouth and circulate it all over their bodies. Dolphins are different from humans in that their nostrils grow on their heads, so when they take a breath, they will leak their heads out of the water, first discharge the waste gas in their bodies, then inhale a large amount of oxygen, and finally enter the water for activities.

Dolphins are marine creatures of mammals, so their reproduction methods are very similar to those of other mammals. When dolphins reach a certain breeding age, they will mate. Male dolphins usually leave after mating, while female dolphins go through the process of pregnancy and childbirth, which lasts for about 11 months. Dolphins give birth in a similar way to humans. When giving birth, young dolphins will show their tails first and their heads will come out last.

Newborn dolphins usually weigh only about 10 kg. As mammals, female dolphins will always take the dolphins with them until they learn predation and other survival skills before leaving. Typically, females guard their calves for about three years, during which time they protect them from other large creatures.