Acanthodoris pilosa (Abildgaard in Müller, 1789)

6 July, 2014.
Greenends Gully, Eyemouth on the east coast. 
1 x 20 mm and 1 x 15 mm together at 12 m; spawn seen elsewhere. Water temperature 12°C.
Sony α6000  in Nauticam housing, 18-55mm 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