Silent filters of the deep: A massive cushion sponge, found amidst forests of seaweed, which feeds by filtering seawater through its chimney-like pores.

A large "cushion sponge" (*Sarcotragus foetidus*)—one of the most characteristic invertebrates found on the reefs of the Mediterranean and Aegean—is visible, growing in a spherical or cushion-like form. On the surface of the sponge, there are distinct, dark-colored, chimney-like respiratory openings (oscula). The organism is surrounded by a dense forest of marine algae and branching, intricate hydroid structures.