Crater Sponge – Hemimycale columellav

Width up to 30cm Thickness 1cm. This sponge encrusts rocks in thick, soft layers. It has a honeycomb texture which varies in colour from red to pale orange, yellow or pink. The depression craters are highlighted by a light coloured ridge. The depressions contain the inhalant pores, and are covered by a fine, gauze-like mesh.

It filter feeds by drawing water in and filtering out microscopic food particles. Found attached to rocks and boulders on the lower shore. Common and widespread from south-east England to north-west Scotland, and the Irish coasts except the east.