Biology of a sponge
• Sponges obtain their food by filtering microscopic food particles from the water. In some habitats they are the dominant filter-feeding organism. They are somewhat distinctive from other filter feeding organisms (clams, barnacles, sea squirts) in that they can filter even microscopic food particles down to the size of bacteria. Scientists have discovered that many sponge species contain symbiotic algae that can also help provide nutrition.
• Sponges also pump remarkable quantities of water through their complex system of canals and chambers. Water is pumped through small openings on the side (ostia), filtered through a maze of canals and chambers, and then expelled through larger openings on the top of the sponge. Water is driven through the sponge by special cells equipped with a twirling, whip-like filament (flagellum).
• The sponge's canals and chambers provide habitat for a myriad of small shrimp-like and worm-like organisms. In a way, sponges can be thought of as apartment buildings for these organisms. The inhabitants do not appear to cause any harm.
• Bath sponges may be the first non-edible product harvested from the sea.
• One of the first drugs for successfully treating cancer, cytosine arabinoside, was isolated from a Caribbean sponge, Cryptotheca cripta.
• It is thought that some sponges live over 100 years.
• Sponges are remarkable pumping "machines." Sponges can pump 10,000 times their own size (volume) in water in one day.
• A sponge the size of a gallon milk container could pump enough water to fill a residential small size swimming pool within one day.
• Recent research has shown that shallow-water sponge populations in the Keys are much more dynamic than previously thought to be.
• On average there are approximately 13 sponges to the pound.
• Because of their sessile nature, biologists once considered sponges to be plants but they are indeed a part of the animal kingdom.
• Sponges are considered to be a colony of single-celled organisms that work together in a coordinated fashion to survive.
Source: University of Florida