Question

Select the incorrect option regarding the benefit obtained by the commensal from their host organism.

• A. Benefit to orchids from the mango tree - Support
• B. Benefit to barnacles from the whale - Access to plenty of food
• C. Benefit to clown fish from the sea anemone - Protection
• D. Benefit to egret from the grazing cattle - Protection

Answer 1

The correct option is D Benefit to egret from the grazing cattle - Protection

Commensalism is a type of interspecific interaction in which, out of the two interacting species, one is benefited and the other is neither benefited or harmed. The organism that gets benefitted is called commensal and the organism that does not derive any benefit neither gets harmed is called as host.

Let us consider some of the examples of commensalism:

• Some orchids grow as epiphytes on the branches of a mango tree. Epiphytes are plants that grow upon other plants only for support. In this case orchids are commensal organisms as they are benefited from the mango tree as it provides support.
• Certain barnacles are found attached on the back of the whales. The barnacles benefit from this interaction as they find a stable place to live, a free ride and access to plenty of food.
• The clown fishes live very near to the sea anemone as they get protection from the predators because of the stinging tentacles of sea anemones. The clown fish is a commensal organism in this interaction as it is getting benefited.
• The cattle egrets (birds) and the grazing cattle also exhibit commensalism. Egrets are birds that are usually found along with the grazing cattle. The cattle egret is commensal in this interaction as it is getting benefited. While grazing, the cattle stir up and flush out insects from the vegetation which the bird feeds on.

Hence, option d is incorrect as the benefit provided by the grazing cattle to the egret is not protection.