Barrel Sponge

Photo: Thibaud Rossard · CC BY-NC

Barrel sponges at New Guinea Reef attain exceptional size — some specimens exceed 1.5 metres in diameter and likely represent centuries of growth, earning them the nickname 'redwood trees of the reef'. These filter feeders pump thousands of litres of water daily through their bodies, playing a critical role in nutrient cycling on the wall. Their cavities shelter hawkfish, gobies, and brittle stars that use the sponge structure for both protection and access to the filtered water flow.