A common, southern and western species, the Elephant's Ear Sponge, Pachymatisma johnstonia is, as its name suggests, a distinct grey colour. It can also be massive - up to 1m across although more commonly 50cms. Smooth and hard, its shape is very variable with lobes and ridges. Covered in oscules (inlets and outlets) mainly along the tops of its ridges. Seems to prefer areas of high water movement but can also be found occasionally in very sheltered locations.
Not found in the North Sea.