Doto fragilis (Forbes, 1838)

27 April, 2013.
Sgeir Port A'Ghuail, Loch Fyne on the west coast. 
15 mm animal on a hydroid at 12 m. Water temperature 7°C.
Sony NEX-5 in Nauticam housing, 18-55mm lens, SubSee +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