The Competition for Seashells: Hermit Crabs vs Fish

Hermit crabs use old seashells for shelter and protection. These small crustaceans have a soft, vulnerable abdomen that they protect by finding an empty seashell to hide in. As the hermit crab grows, it must search for a larger shell to move into, leaving the old one behind for smaller crabs to use. This process of finding and switching shells is essential for the survival of hermit crabs in the wild.

Similarly, some species of fish also use abandoned seashells as a place to hide from predators. These fish find shelter in the empty shells, blending in with their surroundings to avoid detection from larger predators. By utilizing the seashells as hiding spots, these fish increase their chances of survival in the harsh underwater environment.

Which of the following statements is true?

A. Hermit crabs and fish that hide in shells cooperate with each other for food.

B. Hermit crabs and fish that hide in shells compete with each other for shelter.

C. Hermit crabs and fish that hide in shells compete with each other for food.

D. Hermit crabs and fish that hide in shells cooperate with each other for shelter.

Which of the following statements is true?

Answer: B. Hermit crabs and fish that hide in shells compete with each other for shelter.

Explanation: Hermit Crabs hides from their predator by hiding in old seashells (e.g those of gastropods) for protection and/or shelter. This is a form of camouflage exhibited by hermit crabs for survival. Now, if peradventure some species also uses the same mechanism for adaptation and survival, vigorous competition will sets in between hermit crabs and those species because the availability of empty shells at any given place depends on the relative abundance of gastropods which is crucial for the survival of both organisms from their predators. Sometimes, they may even have to fight or kill a competitor in order to gain access to the shell that favors them.