Porifera

Apuntes

• Subtopic: Porifera Porifera, commonly known as sponges, are aquatic, sessile animals characterized by several distinctive features. They possess an osculum, which is the large opening at the top of the sponge through which water exits. Additionally, they have numerous pores called ostia that allow water to flow into the sponge's body. Inside, they contain choanocytes (also known as collar cells) equipped with flagella that help generate water currents and trap food particles. An important anatomical feature is the atrium, a central cavity where water circulates after passing through the pores. Porifera are sessile organisms, meaning they are fixed in one place and do not move. Their nutrition is primarily based on filtration, as they filter water to extract microscopic food particles. They are exclusively aquatic, living in marine or freshwater environments. Reproduction can occur sexually or asexually, often involving the formation of plasmation or germ cells. Lastly, porifera exhibit asymmetry, lacking any defined body symmetry.