Marine animals refer to all kinds of animals living in the sea, including vertebrates and invertebrates. There are vertebrates, fish and other large mammals, such as whales and so on; Invertebrates include crustaceans, cephalopods and so on. Penguins, on the other hand, are not marine animals. They live in polar regions and spend most of their time on land.
Although penguins are not marine animals, they do have relatively strong swimming ability. This is because penguins belong to an ancient swimming bird, they have the ability to swim, not the ability to fly. Moreover, their special body structure can also make them swim faster in the water. Their forelimbs, for example, evolved a structure similar to the flippers of pinnipeds, which allowed them to swim more freely in the water.
Penguins are birds, so they belong to birds. As birds, penguins are unlikely to belong to amphibians. This is because birds and amphibians are two different animals, they are animals in different classes, and there is no intersection between them. In fact, birds are much more advanced than amphibians, they are evolved from reptiles, birds have some more advanced body structure that amphibians do not have. The same is true of penguins as birds, which are not amphibians and are much more advanced than amphibians.
