Okenia nodosa (Montagu, 1808)

22 May, 2011.
Lephinchapel, Loch Fyne on the west coast.
7 mm animal at 14 metres. Water temperature 9.5° C.
Sony NEX-5 in Nauticam housing, 18-55mm lens with Subsea + 10 dioptre 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