Coral Reef with Barrel Sponge, Xestospongia testudinaria, Kai Islands, Moluccas, Indonesia

Coral reef with Barrel Sponge, Xestospongia testudinaria, Raja Ampat, West Papua, Indonesia

Group of barrel sponge in the deep reefs of the Banda Sea, Indonesia.

Barrel sponge in the reef with fishes in the Banda Sea, Indonesia.

Top view of a pnk barrel sponge looking like a saucer against the cyan reef bottom, Cenderawasih Bay, West Papua, Indonesia.

Scorpianfish (Scorpaenopsis oxycephalus), inside barrel sponge (Xestospongia testudinaria), Amed, Bali, Indonesia, Southeast Asia, Asia

Grouper (Cephalopholis sp.) inside barrel sponge (Xestospongia testudinaria), Amed, Bali, Indonesia, Southeast Asia, Asia

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

Diver looks down on blue seastar (Linkia laevigata) on a barrel sponge (Xestospongia sp.) Komodo, Indonesia, Pacific Ocean.

Thousands of scalefin anthias (Pseudanthias squamipinnis), hovering over corals and barrel sponge, Puerto Galera, Mindoro, Philippines, Southeast Asia, Asia

Barrel sponge (Xestospongia muta), large barrel sponge in spur and groove reef, Little Cayman Island, Cayman Islands, Caribbean

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

Barrel sponge (Xestospongia muta), large barrel sponge in spur and groove reef, Little Cayman Island, Cayman Islands, Caribbean

Barrel sponge (Xestospongia muta), large barrel sponge in spur and groove reef, Little Cayman Island, Cayman Islands, Caribbean

Female diver with a lamp looking at a Barrel Sponge (Xestospongia muta) in a multi-coloured coral reef with various sponges and corals, Hopkins, Dangria, Belize, Central America, Caribbean

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

The Hairy Squat Lobster (Lauria slagiani) is found alone, and in pairs, on the outside of barrel sponges belonging to the genus Xestospongia. They are tiny (one centimeter across) and difficult to find on the folds of the sponge, Philippines

Sabre squirrelfish;Sargocentron spiniferum) having found refuge in a huge barrel sponge;Xestospongia testudinaria) at the mouth of the S-shaped pass at a depth of 50 meters. Mayotte