Parasitism is an interaction between two species in which one (the parasite) benefits while the other (the host) is harmed.
An example of parasitism is between Pearl fish and Sea Cucumber. The Pearl fish live in the Sea Cucumber's cloaca which they enter through the anus. The Pearl fish then breaks through the respiratory membrane and situates its home.
Strangler fig grows on the branches of a tree and then the strangler fig eventually sprouts aerial roots. Over time, many roots may grow and then will wrap around the tree resulting in death of the tree.