Members of Chordata may live in aquatic environments if they are invertebrate fish or in land environments if they are vertebrates. They include marine animals, amphibians, birds, reptiles and mammals. There are several classes of Chordata that include Mammalia, Aves and Agnatha.
Some members of Chordata have special habitat needs based on their metabolisms. Adult amphibians have skin that is water permeable and requires a moist environment to prevent desiccation. Those in the subphylum Cephalochordata are found in shallow water environments. Some classes of Osteichthyes are found in freshwater in drier areas and are able to function on both land and in water.