Adalaria proxima (Alder & Hancock, 1854)

27 March, 2013.
Whale Skerries, Sound of Jura on the west coast. 
20 mm animal, one of several including white examples, on kelp at 4 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