ACME SMART PUBLICATION
Phylum Porifera
This animal group comprises Sponges and is thought to be the oldest on the planet. Sponges are the most basic multicellular creatures. They don't have any tissues or organs, despite being multicellular. Sponges need to be near water, thus they dwell in an aquatic environment. Water is essential for nutrient absorption, gas exchange, and excretion. The sponges' bodies have numerous holes or pores known as Ostia. Sponge bodies are built so that water can circulate through them, filtering out food and absorbing dissolved oxygen while also removing waste.This phylum of organisms lacks a specialized digestive, neurological, or circulatory system. Instead, they have a canal or water transport system that performs the activities of digesting, excretion, and gas exchange.
Their bodies are asymmetrical, and their design has been optimized to facilitate the most efficient flow of water via the core hollow that is present inside. Bacteria and other food particles found in the water are their main sources of nutrition. The spongocoel is a huge central hollow canal in their bodies. Water enters the spongocoel through the Ostia and exits through the osculum. Choanocytes or collar cells, with their flagellum jutting out, line up the spongocoel and canals.The water is moved throughout the sponge's body by the beating of this flagellum from all choanocytes. Common examples areSycon (Scypha), Spongilla (Freshwatersponge), and Euspongia(Bath sponge).
