Polycera quadrilineata(Müller, 1776)

8 July, 2015.
Leehinish, Sandray in the Outer Hebrides on the west coast of Scotland.
10 x 12-22 mm animals feeding on the encrusting bryozoan Membranipora membranacea on kelp blade at 10 metres.
Water temperature 11°C.
Sony α6000  in Nauticam housing, 18-55 mm 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