The sun sponge is named for its unusual lifestyle. It is one of the very few sponges that can tolerate exposure to the sun and air. Nearly every other sponge will die when air gets into its body. Most sponges are damaged by direct exposure to sunlight, and much of their bright coloration helps protect them from sunburn. Sun sponges grow attached to oysters or other hard substrates. The sponge is usually light yellow and shaped like a mat, with many stubby fingers sticking up from its surface. Sponges are filter-feeding animals. They are the simplest, and probably most ancient, form of animal life on Earth.