proto-cooperation
An example of this relationship is the interaction maintained between the sea anemone and the paguro (crab), a crustacean that lives inside empty gastropod shells, allowing the existence of anemones on the structure of the shells. Cnidarians protect the pagurus against predation, due to the presence of stinging substances contained in their tentacles. When crabs move in the marine substrate, anemones have a greater chance of obtaining food and propagation, even though, through reproduction, the indirect development of the free-living larval form provides greater dispersion.
Another biotic circumstance occurs through the affinity between crocodiles and the toothpick bird. The birds feed by removing food scraps between the crocodile’s teeth, while sleeping with their mouths open, ridding them of unwanted parasites.