Sycon is a genus of calcareous sponges belonging to the family Sycettidae. These sponges are small, growing up to 7.5 cm and having length from 2.5 to7.5, and are tube-shaped and often white to cream in colour. They are known to aquarium hobbyists as "Pineapple" or "Q-Tip" sponges, and are frequent "hitchhikers" accidentally brought in.