"Sponges"

Body Type: Simplest multicellular animals with a body full of pores and canals.

Symmetry: Mostly asymmetrical (some radial).

Tissues: No true tissues or organs (cellular level of organization).

Skeleton: Made of spicules (calcium carbonate or silica) or spongin fibers; no spine or bones.

Movement: Sessile (fixed in one place) as adults.

Feeding: Filter feeders — draw water through pores to trap food particles.

Digestion: Intracellular, done by choanocytes (collar cells).

Circulation: No circulatory system; water flow distributes food and oxygen.

Reproduction: Both asexual (budding, fragmentation) and sexual (gametes).

Nervous System: Absent.

Habitat: Mostly marine, few freshwater species.

Examples: Sycon, Spongilla, Euspongia (bath sponge).