Diaphorodoris luteocincta (M. Sars, 1870)

27 March, 2013.
Whale Skerries, Sound of Jura on the west coast. 
6 mm animal, one of many including mating pairs on rock surfaces, between 12 and 25 m. Water temperature 6°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