Barrel Sponge

photo of a barrel sponge

Giant barrel sponge Xestospongia muta

Giant barrel sponges are common inhabitants of coral reefs, especially in the Caribbean.  Not only are they the largest sponges on the reef, but they also are very long lived – up tp thousands of years.  Like most sponges, they pump water through their bodies to obtain food: plankton, bacteria and nutrients from the seawater.

Sponges are the heroes of the reef: the number of these large sponges pumping and filtering seawater has a big effect on the coral reefs where they live. Scientists have found that sponges are key recyclers on the reef and provide nutrients to all the other reef organisms. Ever since Charles Darwin observed that coral reefs were like oases in the ocean desert, scientists have tried to discover the secrets of the food cycle on a coral reef. Now they know that sponges are the key.

Read more from BBC News: Sponges help coral reefs thrive in ocean deserts.
Watch the Shape of Life video “Filter Feeding Made Visible.”
Watch the Shape of Life video “the Sponges Wild Ride” showing how particles pass through sponges.
NOAA has created a lesson plan about filter feeding in sponges.