chemosynthetic microorganisms
These brilliant red feathers are actually animals called tube worms. They live in an extreme environment on the deep ocean floor, thousands of meters below the waters surface. Their world is always very cold and completely dark. Without sunlight, photosynthesis is not possible. So what do organisms eat at these depths? Tube worms depend on chemosynthetic microorganisms that live inside them for food. In this and other ways, tube worms have adapted to the extreme conditions of their environment.