Brown-lined Paper Bubble

Found in shallow waters, around weedy areas of rock pools and sand flats.
They feed on polychaete worms.

Cephalaspidea or Head Shield Snails are of the Opisthobranchia group, some of which still have a shell. The head shield from which this group attain their name, is a broadened part of the head, used to dig into the sand and protect the snail.

All opisthobranchs are hermaphrodites.

These beautiful slugs are usually brilliantly coloured as a deterrent against opportunistic predators. Some sea slugs secrete acid from stinging cells in their tentacles while others secrete acid from cells in their mantle.
They are slow moving, can swim or be propelled along either by muscular contraction or by millions of tiny hairs on the bottom of a fleshy 'foot', they have a voracious appetite and feed with a rasp like tongue.
They lay their eggs in a ribbon effect on the sand, in different colours depending on species.
Their main predator are other Sea slugs.