Okenia nodosa (Montagu, 1808)

22 February, 2015.
Lephinchapel, Loch Fyne on the west coast .
A pair of 20 mm animals at 12 metres. There were many of these about on the smooth silt covered rock between 7 and 14 m. The largest specimen was approx. 25 mm long. Water temperature 8°C.
Sony α6000  in Nauticam housing, 50 mm Zeiss Touit macro 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