Polycera quadrilineata(Müller, 1776)

2 September, 2016.
Black Carr, St. Abbs on the east coast.
10 mm animal 14 metres. Water temperature 12°C.
Sony α6000  in Nauticam housing, 50 mm Zeiss 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