Commonly found on the roof of caves, the Leucetta sponges are brittle, with interior structures made from spicules that contain calcium carbonate. Sponges are extremely interesting animals; they have no internal organs, and all life functions are performed by individual cells. There are numerous specialties among the cells, which come together to form the sponge. Even after being separated from each other by being pressed through a sieve, sponge cells will come back together and reform a new sponge.

This sponge was photographed under a lava ledge in about 35 feet of water off the south Kohala Coast near Puako Beach on the Big Island of Hawaii.