It is a interaction between two organism, in which one species is benefited and the other is neither harmed nor benefited under normal conditions.

Examples of Commensalism

(i) Clown fish living among tentacles of sea anemone: The anemone protects the clownfish and provides a safe place to sleep and breed.

(ii) Pilot fish (Remora) accompanies sharks: pilot fish feeds on falling pieces of food when the shark is eating the prey.

(iii) Orchid growing on mango tree: the orchid is benefited as it gets support while the mango tree remains unaffected.

(iv) Sea anemone on the shell of hermit crab: sea anemone is sedentary while hermit crab is free swimming. Hermit crab resides in an empty snail shell for protection and sea anemone also uses snail shell as portable home. Anemone is benefited as it is able to find more food.

(v) Barnacles on back of whales: Barnacles are arthropods. When the whales swim into plankton-rich waters to feed the barnacles also get food. They also get protection from predators.

(vi) Egret and grazing cattle: egrets are small white birds follow herds of livestock to eat the grasshoppers that are stirred up by the cattle’s hoofs.