Commensalism

Commensalism (barnacles and wood)

Commensalism refers to the biological relationship between individuals of two species in which one benefits from the other without harming them. The commensal is the species that benefits from the relationship, while the host is the one that provides while remaining unaffected. Commensals usually obtain nutrients, shelter, support, or locomotion from their hosts. They gain morphological adaptation thanks to their host as well. The picture shows barnacles stuck on a wooden pier post. This can be labeled as a commensalism because the barnacles obtain nutrients from the wood while the post remains directly unaffected by them.