JAMB - Biology (1999 - No. 38)
The sign + is used to indicate an association where an organism gains, while 0 is used where an organism is unaffected. An association indicated as +0 is known as
predation
commensalism
parasitism
competition
Explicació
Commensalism refers to a relationship where one organism benefits from another organism without harming or benefiting the latter; a classic example is the relationship between remora fish and sharks, where the remora attaches itself to the shark and eats scraps of food left behind by the shark while the shark is not significantly affected by the remora's presence.