Elephant Ear Sponge
Pachymatisma johnstonia
Named for its flattened shape and wrinkled surface, this sponge varies from greyish to purplish in colour. Like other sponges, it filters large volumes of water to extract plankton. Near Lihou, you might find it on vertical rock faces or in dim crevices at the lowest tides, forming lumpy patches that feel rubbery to the touch.
- Habitat: Lower shore to subtidal rocky habitats, often in shaded crevices.
- When to See: Year-round
- Length: Can reach ~20–30 cm across and a few cm thick