Also known as Blue Doris, Blue-lined Nudibranch, Blue-lined Sandflat Snail, Bluemargin Sea Slug, Blue Velvet Nudibranch, Blue Velvet Sea Slug, Blue Velvet Slug, Gardiner's Philinospsis, Hammerhead Nudibranch, Hammerhead Sea Slug, Tailed Slug, Velvet Blue Nudi, Velvet Nudibranch.
Found singly or in pairs burrowing amongst corals, rocks and sandy areas of coral and rocky reefs.
They feed on sea hares and sea slugs.
Length - 4cm
Depth - 2-20m
Widespread Indo-West Pacific
Often referred to as 'Nudibranchs' (but they are not), 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. (edit) Ref: http://www.seaslugforum.net/find/philgard