Dolphins belong to the Delphinidae family. They live in seas, oceans and rivers of the world, where they prefer to live in groups. They are carnivorous and communicate through echolocation, an ability to communicate by locating sounds that few species in the world use.
Now then, when you think about the characteristics of this species, do you consider that the dolphin is a mammal or a fish? On our site we tell you all about these classifications of the animal world and reveal to which dolphins belong. Keep reading!
What is a mammalian animal?
Mammals are a class of vertebrate animals. Mammals are diverse, because the species are very different from each other. However, there are some characteristics of mammalian animals common to all of them:
- They feed the young through mammary glands.
- They breathe through lungs.
- The young remain with their mothers for some time after birth.
- They have a skeleton.
- Most have hair.
- The bones of the teeth are attached to the skull.
- They reproduce by internal fertilization, that is, they are sexually reproducing animals.
- The skin is capable of thermoregulation.
- Most mammals are terrestrial.
But not all mammals are land animals. There are also flying mammalian animals, as you can read in this other article on our site about Flying Mammals - Examples, characteristics and images.
What is a fish?
Now, before explaining whether the dolphin is a mammal or a fish, you also need to know the characteristics of fish. Fish are vertebrates, but they differ from mammals on several points. The main characteristics of the fish are:
- They only live in water.
- They breathe through gills.
- They have scales and fins.
- Not all species have jaws or teeth.
- The young hatch from eggs and feed on different things: algae, detritus, the yolk sac, among others.
- They reproduce by external or internal fertilization.
- Your body temperature varies from that of the water.
Taking these characteristics into account, in which one would you include the dolphins? We reveal it below!
Is the dolphin a fish or a mammal?
Dolphins live in s alt or fresh water They also have lungs, but they don't breathe through the nose, but through the spiracle, a hole found in the head. They reproduce by internal fertilization and take care of the young, but they have fins. Furthermore, they are among the few animals that masturbate.
So, is the dolphin a mammal or a fish? Dolphins are marine mammals, a group that includes other species, such as otters, manatees, whales and walruses. In turn, dolphins belong to the infraorder of cetaceans, which appeared on the planet 54 million years ago. The infraorder of the cetaceans is divided into two groups:
- Mysticetos: like whales.
- Odontocetes: such as dolphins, killer whales and sperm whales.
For more information, you can read this other article on our site on How do dolphins reproduce and are born?
Dolphin Characteristics
Dolphins are cetaceans or marine mammals. As such, they have some characteristics that distinguish them:
- Respiration: Unlike land mammals, the pulmonary system is not divided into lobes. Furthermore, land mammals have lobules and bronchioles in the pulmonary system, while marine mammals do not. On the other hand, they breathe through the spiracle of the head and must come to the surface to obtain oxygen.
- Speed: they have fins like fish, but the body is more aerodynamic, since, being heavy, their body needed adaptation to reduce resistance to sea currents.
- Skin: Their skin is hard and, under it, they have a layer of fat that allows them to conserve body heat.
- Oxygen: they have myoglobin in the muscles, a protein capable of storing oxygen. Thanks to this, they are able to store it to submerge in the water.
- Communication: Communicate via sonar. In addition, since the dolphins' trachea is short and they communicate with the spiracle, instead of the esophagus.
- Temperature: Your average body temperature is 37°C.
- Food: they only feed on meat when they reach adulthood, while there are fish and land mammals with varied eating habits.
- Brain: The brain is much more developed than in fish, and larger than that of some land mammals.
- Habitat: they can only live in water, as their skin dehydrates outside of it. In contrast, many land mammals use water only for drinking and cooling.
- Synchronization: They are able to establish synchronous breathing when swimming in a group.
Now that you know that the dolphin is not a fish, but a mammal, you may also be interested in this other article about 10 curiosities about dolphins.
