Favorinus branchialis (Rathke, 1806)

23 June, 2015.
The Aurania, NW Mull on the west coast .
10 mm animal at 18 metres.
Water temperature 10°C.
Sony α6000  in Nauticam housing, 18-55 mm lens, Nauticam CMC-1 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