Tình bạn "lạ thường"
Giáo trình Apax English ngoài cung cấp các kiến thức về ngôn ngữ học còn chứa đựng rất nhiều kiến thức về khoa học. Bài học "The Unlikely Friendship" (Tình bạn lạ thường) chỉ về mối quan hệ cộng tác giữa những loài cá to và cá nhỏ tại đại dương.
Fish live in the water, but they need a “bath”every once in a while. Tiny invisible creatures called parasites live on fih skin. If too many of them bind to a fish, the fish can become ill. That’s why fish have to “bathe” occasionally. How do they do it? They go to “cleaning stations.” Many large fish, including sharks, have a friendly relationship with “cleaner fish.” Cleaner fish are small species of fish that feed on parasites.
When a large fish has too many parasites on its skin, it visits a cleaning station. Cleaner fish live at the cleaning station and wait for larger fish to arrive. When a large fish goes to a cleaning station, it makes a signal indicating that it needs a cleaning. This is often done by opening its mouth
wide and gently swimming in place. Then, several cleaner fish begin washing the large fish. They gently eat all of the parasites living on the large
fish’s skin. Sometimes, they even go into a large fish’s mouth to clean its teeth as well.
Normally, large fish hunt smaller fish. However, at cleaning stations, large fish never eat cleaner fish. Large fish benefit from cleaner fish because they get a free cleaning. Cleaner fish benefit from cleaning large fish because they get a free meal. This kind of cooperative relationship between animals is called “symbiosis.” Examples of symbiosis can be found everywhere in nature.
Even animals understand that cooperation is sometimes better than conflict.