Doris pseudoargus (Rapp, 1827)

30 April, 2011.
Seven Step Reef, Loch Creran on the west coast. 
65 mm animal at 14 m. Water temperature 8.5 °C.
Sony NEX-5 in Nauticam housing, 18-55mm lens and Inon D-2000 flash.

for more information about this species go to one of the links below
OPK - Opistobranquis nudibranchs of the british isles sea slug forum