Dolphins are aquatic animals, living in the same environment as fish, and they have certain similarities with fish in terms of body structure. Therefore, many people will mistake dolphins for fish. However, although dolphins and fish have some similarities, it is only because they live in the same environment, in the long process of evolution led to their body structure convergence, in fact, they are not the same kind of animals. In other words, dolphins are not fish.
In fact, dolphins are different from fish in many key characteristics. For example, most of the reproductive methods used by fish are oviparous, while dolphins are not oviparous. For example, the respiratory organs used by fish are gills, which are also typical respiratory organs of fish. Dolphins, on the other hand, do not have gills, so the respiratory organs they use are not gills. It can be seen that dolphins are quite different from fish and do not belong to fish.
As mentioned above, dolphins do not belong to fish, and there are many key characteristics that are different from those of fish. In fact, dolphins belong to mammals. Unlike land mammals, dolphins live in the water. However, as a group of mammals, dolphins have many key characteristics that mammals share. For example, in terms of reproductive methods, dolphins use viviparous methods and lactation, which is one of the key characteristics of mammals. For example, from the point of view of respiratory organs, dolphins use lungs to breathe, which is also consistent with most mammals. In addition, from the characteristics of body temperature, dolphins belong to homeotherms.
