Commensal

Commensalism is a type of symbiotic relationship between two living organisms where one organism benefits from the other without affecting it. The term "commensal" is derived from the Latin word "commensalis," meaning "sharing a table." In this relationship, the commensal organism may obtain nutrients, shelter, support, or locomotion from the host organism, which remains unaffected by the interaction.

Characteristics of Commensalism

Commensal relationships are characterized by the following features:

• One-sided benefit: The commensal organism derives some benefit, such as food or shelter, while the host organism does not experience any significant positive or negative effects.
• Non-harmful interaction: The host organism is neither harmed nor helped by the presence of the commensal organism.
• Close association: The commensal organism often lives in close proximity to the host, sometimes even on or inside the host's body.

Examples of Commensalism

Remoras and Sharks

Remoras, also known as suckerfish, attach themselves to larger marine animals like sharks using a specialized sucker on the top of their heads. The remoras benefit by gaining free transportation and feeding on the scraps of food left by the shark. The shark is generally unaffected by the presence of the remora.

Barnacles and Whales

Barnacles often attach themselves to the skin of whales. The barnacles benefit by being transported to nutrient-rich waters where they can filter-feed. The whale is not significantly affected by the barnacles.

Epiphytic Plants

Epiphytes, such as certain orchids and ferns, grow on the surface of trees. They benefit by gaining access to sunlight and air without harming the host tree. The tree is not affected by the presence of the epiphytes.

Distinguishing Commensalism from Other Symbiotic Relationships

Commensalism is one of several types of symbiotic relationships, which also include:

• Mutualism: Both organisms benefit from the relationship.
• Parasitism: One organism benefits at the expense of the other.

Also see

• Symbiosis
• Mutualism
• Parasitism
• Amensalism
• Ecology