1 Piece Cuttlebone Prepared for Aquarium Use - Natural Mineral Supplement for Aquarium Snails, Shrimp, Crayfish, and Crabs by Aquatic Arts Provides necessary minerals for healthy shell growth in aquatic snails, and healthy carapace development in crustaceans. Helps prevent shell breakages, cracks, and subpar growth in Aquatic Snail shells. Can be added directly to aquarium filter, or boiled and added to aquarium for grazing. Will float unless boiled or soaked for 10+ days in water. One cuttlebone lasts over a year in most aquariums.