are orange-pink, encrusting or massive sponges that form mounds with vertical extensions. The extensions sometimes exhibit longitudinal grooves, are finely rough with stiff hairs and are usually orientated towards the water surface whatever the angle of the substratum. The excurrent openings (oscula) are small and scattered about the body of the sponge. Desmacidon fruticosum
produces large quantities of mucus when out of water.