Giant Barrel Sponge. Xestospongia testudinaria. Modern. Philippines

Measures 22 x 22 x 22in - Estimate: $400 - 500 - Unsold.

Note : Sponges are primitive filter feeders that pump water through their bodies to filter out particles of food matter. With no true tissues, they lack muscles, nerves, and internal organs. Their similarity to colonial choanoflagellates shows the probable evolutionary jump from unicellular to multicellular organisms. However, recent genomic studies suggest they are not the most ancient lineage of animals, but may instead be secondarily simplified. There are over 5,000 modern species of sponges known; they can be found attached to surfaces anywhere from the intertidal zone to as deep as 29,000 feet or further. The present impressive specimen is a large example of the giant barrel sponge. (Copyright © 2002-2008 Bonhams 1793 Ltd., Images and Text All Rights Reserved) 

Bonhams. Natural History, 22 Jun 2008. 220 San Bruno Street, San Francisco // 7601 Sunset Blvd., Los Angeles - www.bonhams.com