I think what you are asking for is amphibian. An animal capable of living both on land and in water.
The science is called Taxonomy.
They are called fossils you idiot.
A mutually beneficial relationship between two biotic (living) organisms is called a symbiotic relationship.
invection
Transpiration
Creatures that live only in water are referred to as aquatic.
Aquatic animals
Why not? You can call the container whatever you wish. (A tank? Glass Box? Vivarium? etc.) It actually only becomes an "Aquarium" when it is used for keeping water living creatures in, and the "Aqua" is added. The latin word for water is AQUA. Hence an 'aqua-rium is a container of/for water.
Aquatic
You can call it anything you want!
non living things
its called marine life.smart aleck
Amphibian
Amphibians
I suppose you could call the crayfish the cousin of the lobster. Crayfish certainly look like lobsters. But they are fresh water animals and lobsters are salt water creatures.
veterbrates
Animals that possess a backbone are known as vertebrates. This group includes mammals, birds, reptiles, amphibians, and fish.