David Hall's Encounters in the Sea Photography
Symbiosis
Symbiosis means "living together". Symbiotic relationships are very common in the ocean, especially among animals living on coral reefs. There are several kinds of symbiosis: "mutualism" is a partnership in which both animals benefit; "parasitism" is a relationship in which one animal benefits at the expense of the other; "commensalism" is a term used to cover all other kinds of symbiosis - usually relationships where one partner benefits, while the other is neither helped nor harmed.