The gelatinous to rubbery consistency lends texture to soups. The sheen on some jelly-like gelatinous lichens is created by mucilaginous secretions. Agar is a gelatinous substance derived from seaweed. Such textures may include crispy, chewy, slippery, soft, hard, velvety, gelatinous, and runny. Soluble fiber dissolves in water to form a gelatinous material. Microscopically, the hyphae are clamped and occur in a dense gelatinous matrix. Fish otoliths accrete layers of calcium carbonate and gelatinous matrix throughout their lives. Other food sources of the albacore include fish, crustaceans, and gelatinous organisms. Its body chamber is covered by a thick, gelatinous, and slippery periostracum. The conjunctiva becomes swollen and gelatinous in appearance. Salps move by pumping waters through their gelatinous bodies. When alkali is added to solutions of soluble Fe(III) salts, a red-brown gelatinous precipitate forms. In pelagic species this tissue is gelatinous and buoyant. Gelatinous lichens may appear leafy when dry. Occasionally, they are also seen feeding on gelatinous zooplankton such as hydromedusae and ctenophores.