Dolphin mammal why

Whales and porpoises are also mammals. There are 75 species of dolphins, whales, and porpoises living in the ocean. They are the only mammals, other than manatees, that spend their entire lives in the water. Home Ocean Facts Are dolphins fish? Because a dolphin's eating and breathing remains separate, they can swallow prey without getting water into their lungs. Dolphins also have collapsible lungs to avoid suffering decompression sickness when they dive deeper than normal.

Collapsible lungs allows dolphins to breathe much more quickly than humans. Learning more about how these amazing lungs function under extreme pressure may help researchers develop technologies to reduce risks to humans in similar situations. All mammals give birth to live young. Reptiles, amphibians, fish and insects lay eggs that hatch at some point in the future. Although birds are warm-blooded, they are neither reptiles or mammals but belong in their own group.

Sexual maturity of dolphins varies, and is related to the size of the animal, not age. A dolphin pregnancy last around 12 months. Female dolphins can realistically bear calves once every 2 to 4 years but the average interval between dolphin births is three years. Dolphin calves have hair on their rostrum when they are born, which falls out soon after birth. However, you can still see hair follicles through adulthood. Dolphins do not need hair to maintain body temperature since they have plenty of blubber to keep organs warm.

Evolutionary biologists think that the presence of dolphin body hair at birth indicates the ancestors of dolphins land mammals had hair to help them maintain body temperature in colder environments.

Marine mammals that live on land and in water use fur as a primary means of insulation. However, blubber is the primary means of insulation for most marine mammals, including dolphins. A mammal is a member of the class Mammalia. You can tell that a dolphin is a mammal because it has a number of characteristics that are only found in mammals rather than in fish, or any other kind of animal. You can find out more about mammal characteristics here: What Is A Mammal?

In fact, having hair — or at least, hair follicles — is one of the defining characteristics of a mammal. No other type of animal has hair. However, they do have hair follicles. Some scientists think that these act as sensory organs. Some river dolphins do have small hairs on their snouts.