Giant barrel sponges are actually animals, despite the fact that they grow fixed to the reef or the ocean bottom, giving us the impression that they are plants. They are impressive in their size and their presence in the underwater world, but the facts about them and their importance to the health of the reef and the ocean is truly surprising. Scientists estimate their life span can be well over 2000 years of age. The oldest known living creature was a barrel sponge that died only a decade and a half ago, with an estimated age of 2300 years. Compared with the Galapagos tortoises at approximately 200-250 years of age, or blue whales at approximately 200 years of age, they easily exceed the life span of any known animal on the planet by many times. Even the giant redwood trees of British Columbia and western United States have been recorded to only 2000 years. Aside from some strains of bacteria, these sponges are oldest known living things we have ever seen.
One of the most amazing things about these animals is that their cells are not specifically limited to one purpose like most animals. All cells of the giant barrel sponges are capable of serving the purpose of any other cells. For this reason, they are capable of regeneration and regrowth. In laboratory settings, sponges that have been pulverized in a blender showed the ability to reform into a barrel sponge again. Learning how this is done may some day play a vital role in our own healing and regeneration.
These barrel sponges were filmed on the wall and reef surrounding Little Cayman Island. Barrel sponges are filter feeders that play a crucial role in the ocean and the environment. Removing bacteria and contaminants from the ecosystems, they are essential to the health of many other reef inhabitants. They can live in shallow water or in depths of up to 400 feet. Prominent in most tropical waters, they provide a service to a large part of our planet. They grow to six feet in diameter and are habitats for fish, crabs, shrimp and many other tiny organisms. Spectacular sights for scuba divers, they are a source of fascination and wonder for those who venture into the underwater realm. Few experienced divers have not paused at one time or another to admire the majestic giant barrel sponges and wonder just how long they have been alive, as well as how long they will be alive after we are gone.
As robust and resilient as they are, human-caused changes to the environment are not seriously affecting them and becoming a threat to their survival. Without them, the survival of the reefs and our entire ecosystem is unlikely.