Polycera quadrilineata (Müller, 1776)

9 April, 2011.
Dunmore Reef, Canna on the west coast.
30 mm animal at 12 metres. Water temperature 7° C.
Sony NEX-5 in Nauticam housing, 18-55mm lens and 2 x Inon D-2000 flashes.

for more information about this species go to one of the links below
OPK - Opistobranquis nudibranchs of the british isles sea slug forum