Would you like to hear about an animal stranger than most science fiction aliens?
Sponges
No, not kitchen sponges (though cleaning and bath sponges were originally made from their flexible protein skeletons).
Sponges are simple aquatic animals. Their bodies are like balloons full of jelly. The "balloon" is made of layers of cells. Others cells inhabit the jelly and produce its skeleton.
Adult sponges are anchored in place and don't move. But their larvae move by swimming or crawling. Plants feed by capturing solar energy in the process of photosynthesis. Sponges can't do this, although a few species host cyanobacteria that can.
Creative Procreators
If they don't move or photosynthesize, how do they feed themselves? Sponges eat by pumping water through the hollow canals of their porous bodies, using microscopic beating hairs on special collar cells lining the canals. The flow carries particles of food, and oxygen too, into the sponge to be captured by its cells.
Like other animals sponges produce sperm, which can fertilize egg cells in another individual. But, each sponge can function as both a male and a female.
Read More:
- "Introduction to Porifera"Â (University of California Museum of Paleontology)
- "Sponges: They Are Nothing Like Sponge Bob" (The Wonders of the Seas, Oceanic Research Group)
- "All About Sponges"Â (The Tree of Life Web Project)
