One study provides substantial evidence that an individual of this deep-sea sponge, that forms giant spicules up to 3 meters long, is about 11,000 years old.[3]

Five other individuals collected from depths of 1,100 to 2,100 meters at three widely separated locations in the western Pacific Ocean were estimated to be 6,000 to 18,000 (±1,000) years old and grew radially at about 140 μm per 1,000 years.[4] The samples were shown to record deep ocean silica geochemistry throughout their lives.

Owen Trueblood