Barrel Sponge

The barrel sponge is the largest sponge species found in Komodo National Park and one of the most iconic invertebrates on Indo-Pacific reefs. These magnificent filter feeders can grow to enormous proportions, with individual specimens exceeding 1.5 metres in diameter and height, forming massive barrel or vase-shaped structures that become landmarks on the reef. Barrel sponges are extraordinarily efficient water filters — a single large individual can process thousands of litres of seawater per day, extracting bacteria, plankton, and dissolved organic matter while returning clean, filtered water to the reef. In Komodo, large barrel sponges are found on deeper reef walls and slopes, their exteriors often encrusted with other organisms including soft corals, tunicates, and algae. The interior of a barrel sponge is a sheltered micro-habitat for numerous small fish, shrimp, and crabs. These ancient organisms grow incredibly slowly, and a sponge measuring one metre across may be over 100 years old. Their role in water filtration and nutrient cycling makes them unsung heroes of reef health.