Giant sponge showing how it filters water with the use of dye, Dominica, West Indies, Caribbean, Central America

Giant sponge showing how it filters water with the use of dye, Dominica, West Indies, Caribbean, Central America

Giant sponge showing how it filters water with the use of dye, Dominica, West Indies, Caribbean, Central America

Giant barrel sponge (Xestosongia muta), and sunburst, St. Lucia, West Indies, Caribbean, Central America

Giant barrel sponge, Thailand, Southeast Asia, Asia

Giant sponge showing how it filters water with the use of dye, Dominica, West Indies, Caribbean, Central America

Giant barrel sponge, Dominica, West Indies, Caribbean, Central America

Giant barrel sponge (Xestosongia muta), St. Lucia, West Indies, Caribbean, Central America

Crinoids cling to a large sponge on a healthy coral reef near the island of Sulawesi, Indonesia. This beautiful, tropical region is home to an incredible variety of marine life.

Giant barrel sponges on the spectacular walls off the reefs of Turks and Caicos, West Indies, Caribbean, Central America

Sea cucumbers (Synaptula sp.) on giant barrel sponge (Xestospongia testudinaria), Dumaguete, Negros Island, Philippines, Southeast Asia, Asia

Sea cucumbers (Synaptula sp.) on giant barrel sponge (Xestospongia testudinaria), Dumaguete, Negros Island, Philippines, Southeast Asia, Asia

Diver looking at Giant Barrel Sponge (Xestospongia muta) in coral reef, Caribbean, Dominican Republic, Central America

Giant barrel sponge and Unicornfish, Raja Ampat Indonesia