Facelina auriculata (Müller, 1776)

20 October, 2015.
The Hurdles, Scapa Flow in the Orkney Islands.
35 mm animal at 18 metres. Water temperature 11°C.
Sony α6000  in Nauticam housing, Zeiss 50 mm macro 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