Anoxycalyx joubini

The giant volcano sponge is a species of Antarctic sponge. It is one of the largest sponges in the world which can grow up to a diameter of 1.5 metres and 1.95 metres in height. The species may have an extremely long lifespan, with estimates of up to 15,000 years. A. joubini occurs in deeper waters than the similar species Cinachyra antarctica, which is also very long-lived. Antarctic sponges live at below the surface, in extremely cold temperatures and constant pressure. This may slow down their growth rate and other biological processes because one caught specimen of A. joubini did not show any growth in a span of 10 years.