The giant barrel sponge is easily recognized by its barrel or vase shape, with a large opening at the top called an osculum, through which seawater is expelled. It can reach up to 6.6 feet in height, making it one of the largest sponges on tropical reefs along with its Caribbean cousin, the giant Caribbean barrel sponge (Xestospongia muta).

The coloration of the giant barrel sponge generally ranges from reddish-brown to pink, with an opening that is often lighter. Its texture is firm and sometimes slightly stony.

The giant barrel sponge is found in the waters of the Indo-Pacific region, particularly in the Philippines, Indonesia, Malaysia, Australia, New Caledonia, and several areas of the Indian ocean.

The giant barrel sponge grows in clear, well-oxygenated tropical waters, mainly on hard substrates of coral reefs, down to several dozen feet in depth.

The giant barrel sponge often serves as a refuge for many marine organisms, such as crustaceans, fish, and microorganisms, making it a true micro-habitat within reef ecosystems.

Like most sponges, the giant barrel sponge feeds on microscopic plankton and organic particles by filtering the seawater that flows through its walls.

A single sponge can filter large amounts of water, helping to clarify seawater and support the functioning of reef ecosystems.

The giant barrel sponge can reproduce sexually: typically hermaphroditic, it produces both male and female gametes and, after fertilization, gives rise to a larva capable of moving before settling on a substrate and developing into a new sponge.

The giant barrel sponge can also reproduce asexually, by budding or fragmentation, when a piece of the sponge detaches and develops into a new individual.