(d) Streaming body is a secondary aquatic adaption. It is found in animals that live permanently in water but most of them are amphibious in nature. The stream lined body consists of compression of head, body and tail into a curved stream lined form.
There is no protruberance over the body so that the animal can move easily through water. Parasitism is a relationship between two organisms of different species in which one organism called parasite obtains its food directly from another living organism called host.
In xeric adaptation perspiration is reduced to conserve water. Uricotelism is characteristic of terrestrial animals which excrete uric acid.