Giant Barrel Sponge
Giant Barrel Sponge (Xestospongia testudinaria) is a giant species of sponge found in the Indo-Pacific coral reefs. It commonly occurs at depths ranging from over 10 meters to 120 meters and can grow up to a diameter of 1.8 meters. The sponge typically exhibits a brownish-red to brownish-gray coloration, with a hard or stony texture. Due to its impressive size and estimated lifespan of hundreds to possibly thousands of years, the giant barrel sponge has earned the nickname "redwood of the reef." It displays a variable form, often appearing as a large, firm, barrel-shaped structure with a cone-shaped cavity at the top called the osculum. These sponges make beautiful decorative pieces. The specimen in question originates from Luzon, Philippines.