How do barnacles benefit from living on a whale?
The correct answer and explanation is :
Barnacles benefit from living on a whale through a form of commensalism, where the barnacles receive advantages without harming the whale. This relationship provides barnacles with an opportunity to access nutrient-rich waters, which is crucial for their feeding process. Here’s a detailed explanation:
1. Access to Nutrient-Rich Waters:
Barnacles are filter feeders, meaning they feed by filtering plankton and other small organisms from the water. By attaching to the whale, they are carried across various regions of the ocean, including those rich in nutrients. As the whale swims through the water, the barnacles are constantly exposed to water that contains a higher concentration of plankton, which improves their chances of obtaining food.
2. Increased Mobility:
The barnacles benefit from the mobility provided by the whale. Since barnacles are sessile creatures (they cannot move once they attach to a surface), they rely on external factors like water currents to bring food to them. By hitching a ride on a whale, barnacles are carried through different environments where food might be more abundant than in the waters they could access on their own. This movement helps barnacles thrive in otherwise less productive areas.
3. Protection from Predators:
Living on a whale also offers barnacles some protection from predators. While barnacles are usually attached to the whale’s skin, they are not as vulnerable to predators like fish or other marine creatures that might otherwise feed on them. The size and mobility of the whale help keep potential predators at bay, giving the barnacles a relatively safe place to live.
4. Minimal Impact on the Whale:
While the barnacles benefit from living on the whale, the relationship typically has a neutral or even positive impact on the whale. The barnacles do not directly harm the whale in most cases, as they don’t typically cause any significant damage or drain resources from the whale. However, in some cases, heavy barnacle growth may increase drag, potentially requiring the whale to expend more energy while swimming. Nevertheless, this effect is usually minor in comparison to the benefits the barnacles receive.
Thus, barnacles gain food, mobility, and protection without significantly affecting the whale, creating a beneficial symbiotic relationship.