托福口语 Task 4

Today, we're going to talk about a fascinating concept in animal behavior called 'symbiotic mutualism.' This occurs when two different species interact in a way that benefits both. Let me give you two examples from the ocean to illustrate this. First, consider the clownfish and the sea anemone. The sea anemone has stinging tentacles that deter predators. Clownfish, however, have a special mucus coating that protects them from the stings. So the clownfish finds a safe home among the tentacles, and in return, the clownfish chases away fish that might eat the anemone. Also, clownfish waste provides nutrients for the anemone. Second, take the cleaner wrasse. This small fish sets up 'cleaning stations' on coral reefs. Larger fish, like groupers, visit these stations to have parasites and dead skin removed by the wrasse. The wrasse gets a meal, and the grouper gets healthy, clean skin, which reduces stress and improves its overall fitness. In both cases, the interaction is essential—neither species could thrive as well without the other.