The puffball sponge is spherical, with a flat bottom and a rough outer surface that's orange to yellow in color. The body surface contains many tiny pores called ostia, where water carrying oxygen and small food particles enter the sponge. Waving flagella (whips) create a current that keeps the water moving. The water and waste exit the sponge through one or more much larger openings called oscula. On most species of sponges, the oscula are clearly visible, but you need to look closely at the orange puffball sponge to see them.
The body of a sponge is supported by a matrix of fibers made of spongin (a structural protein) and an interlocking skeleton of spicules. High powers of healing and regeneration are within this sponge's sphere. When parts become infected, the puffball uses its spicules to isolate and shed the infected parts, then regenerate the lost parts.
Sponges are an important part of the ecosystem; they're a source of food for nudibranchs, chitons, sea stars, turtles and some fishes.
A sponge's body is a collection of loosely connected, nearly independent cells—it has no organs and no tissues. These are the only animals that if broken into cells can put themselves back together again.
Many biologists have been seeking an animal group that is the ancestor of all animals. When Mitch Sogin, a biologist at the Marine Biology Lab at Woods Hole, compared the genetic blueprint of a sponge with those of other animals, he discovered that all animals with more than one cell are based on a sponge's genetic blueprint.
Scientists have described and named more than 5,000 of the probable 10,000 to 15,000 species of sponges, which come in various shapes and sizes.
Adult sponges are sessile (unable to move about). They produce potent chemicals to defend themselves against other animals that try to overgrow, poison, infect or eat them. These chemicals don't harm the sponges themselves, having the same properties of anti-bacterial and anti-cancerous drugs that don't kill healthy cells. Scientists are researching these chemicals in hopes of finding new disease-fighting drugs.