Polychaetes. This class includes thousands of species, divided into two main groups: the mobile species and species living by attaching to the substrate. The former have vermiform shape with tufts of bristles on each segment of the body. Bristle worm, fiery (Hermodice carunculata) when in contact with them can cause severe pain. Worms, leading a sedentary life, look quite different - they are more like small flowers, crests or plumes. These worms live inside a thin tube, produced by themselves, which is attached to the substrate or, in some cases, completely hidden inside the corals. They feed on plankton, profiltrovyvaya water through their bronchial beams, which are very beautiful and brightly colored. If disturbed, they quickly hide in my pipe.