Phylum Porifera (Sponges)
Sponges are in the phylum Porifera which means "pore-bearers" because sponges have tiny openings , or pores, all over their bodies. Sponges are also sessile, meaning they stay in one spot their entire lives.
Body Plan:
Sponges are asymmetrical. They have no front or back, and no right or left side. The choanocytes are specialized cells that use flagella to move a current of water through the sponge, the water leave through to osculum (Shown on the right). Sponges have a simple skeleton. In harder sponges, the skeleton is made of spiny spicules, spike-shaped structure made of calcium or silica. Feeding:
Sponges are filter feeder that sift microscopic food particles from the water. As the water moves through the sponge, particles are trapped and engulfed by choanocytes that line the body cavity. They are then digested. Archaeocytes complete the digestive process and transport digested food through the sponge. Reproduction:
Sponges can reproduce either sexually or asexually. Sexual: Asexual: Sponges can produce by budding or producting gemmules. Gemmules are groups of archaeotypes that are surrounded by a tough layer or spicules. They can survive freezing temps and drought.
|
Respiration, Circulation, and Excretion:
Sponges rely on the movement of water for their body functions. As water moves through, oxygen dissolved in the water diffuses into the surrounding cells. Carbon dioxide and other wastes diffuse into the water and are carried away Response:
Sponges do not have a nervous system to respond to changes in the environment, however, they protect themselves by producing toxins that make them poisonous to predators. Ecology of Sponges:
Sponges provide habitats for marine animals such as snails, sea starts and shrimp. These are examples of commensalism. Sponges also work together with bacteria, algae, and plantlike protists. These organisms provide food and oxygen to the sponge, while the sponge provides a protection where they can live. This is an example of mutualism, since both benefit. How sponges filter water: http://www.youtube.com/watch?v=T7E1rq7zHLc |