symbiosis
symbiosis, any of several living arrangements between members of two different species, including mutualism, commensalism, and parasitism. Both positive (beneficial) and negative (unfavourable to harmful) associations are therefore included, and the members are called symbionts.
Any association between two species populations that live together is symbiotic, whether the species benefit, harm, or have no effect on one another.
The Editors of Encyclopaedia Britannica This article was most recently revised and updated by Adam Augustyn.
Citation Information
Article Title:
symbiosis
Website Name:
Encyclopaedia Britannica
Publisher:
Encyclopaedia Britannica, Inc.
Date Published:
28 October 2026
Access Date:
November 13, 2026