Sycon raphanus

Sycon raphanus is a species of marine invertebrate, a calcareous sponge belonging to the family Sycettidae. The name derives from the Greek, "raphanus", meaning radish, and presumably refers to the sponge's shape.

Sponges are composed of a jellylike mesohyl sandwiched between two layers of cells. They have a fragile skeleton composed of stiff spicules. They are filter feeders, maintaining a flow of water through their structure which passes out through large openings called oscula.