Encrusting sponges form a kind of crust on the substrate on which they live. This species varies from dark orange to red in colour. It is often found on the valves of sessile shellfish like spondylus or oysters, and is endemic to the Mediterranean.
Scientific name: Crambe crambe
French: Eponge encroûtante orange-rouge
Spanish: Esponja encrostante roja-anaranjada
Italian: Spugna dello spondilo
German: Orangeroter Krustenschwamm