Giant barrel sponge

''Xestospongia muta'', commonly known as the giant barrel sponge, is one of the largest species of sponge found in the Caribbean. It grows at depths of 10 metres or more and it grows between 60 cm and 1.8 m. It is brown-grey to reddish in color, with a hard or stony texture. There is little scientific information about the species, although it has been monitored since 1997.

''X. muta'' has been called the "redwood of the reef" due to its up to 2000 year lifespan as well as its size and color.