The density of seawater is far greater than the density of air. An object moving through seawater produces significantly greater drag than an object moving through air. A dolphin's fusiform shape and its smooth surface texture produce minimal friction and wake, thereby reducing drag. Finally, consider the fact that light does not penetrate very deeply beneath the ocean surface. This means that visibility under water is greatly reduced or eliminated after a few meters.
Dolphins have good vision in light above and under water.
They accommodate for the lack of visibility in deep and murky waters with excellent hearing and by using echolocation. This additional sense enables dolphins to navigate, find prey, and detect predators without relying on vision. Materials Several small scraps of paper for each student, pencils Three paper bags or other small containers to hold the answers. One Review the characteristics of mammals. Explain that physical adaptations include anatomical structures and biological processes, while behavioral adaptations can be both instinctual and learned.