Porifera & Cnidaria

Porifera, commonly known as sponges, are simple aquatic animals characterized by their porous bodies and lack of true tissues and organs.

Porifera are primarily found in marine environments, although some species inhabit freshwater.

Porifera have a unique body structure with a porous body wall, consisting of an outer layer of cells, an inner layer of choanocytes, and a mesohyl in between.

Porifera are filter feeders; they draw water through their pores, trapping food particles with their choanocytes.

Sessile means that Porifera are fixed in one place and do not move; they are attached to a substrate.

Cnidaria are a phylum of animals that include jellyfish, corals, and sea anemones, characterized by the presence of cnidocytes, which contain stinging cells.

A key feature of Cnidaria is their radial symmetry, which allows them to interact with their environment from all sides.

Nematocysts are specialized stinging organelles found in Cnidaria that are used for capturing prey and defense.

Cnidaria use their nematocysts to sting and immobilize prey, which is then brought to their mouth.

The life cycle of a jellyfish includes a polyp stage and a medusa stage, with reproduction occurring both sexually and asexually.