Barrel Sponge (Xestospongia testudinaria)
Image Copyright Jonathan Milnes
Observed: Koh Chang Reefs, October 2015
Observed By: Jonathan Milnes
Xestospongia testudinaria is a species of barrel sponge in the family Petrosiidae. It very closely resembles the giant barrel sponge (after all it is really large and looks like a kind of spongy barrel) but that species is only found in the caribbean sea.
