Ancula gibbosa (Risso, 1818)

22 July, 2001 at 8 mile reef, Loch Etive on the west coast.
At 15 metres in 12° C water, an 18mm long white pigmented individual on a hydroid.
Taken using a Nikonos 5 with 2:1 extension tube and Ikelite 50 flash.

for more information about this species go to one of the links below
OPK - Opistobranquis

 nudibranchs of the british isles sea slug forum