No two lakes are exactly alike, but most have at least four separate habitats.
On the life-rich shoreline, sunlight reaches the bottom and helps plants grow. Farther out toward the center, a lake has layers, kind of like a birthday cake. Sunlight reaches the top two layers, which are filled with insects, plants, and fish. Meanwhile, the bottom layer gets little or no sun. Decomposers wait patiently for their next meal down there on the nutrient-rich floor.