Pleurobranchus membranaceus (Montagu, 1815)

5 February, 2015.
Lephinchapel, Loch Fyne on the west coast.
Underside of a 65 mm animals at swimming 8 metres. Water temperature 8°C.
Sony α6000  in Nauticam housing, 50 mm Zeiss Touit macro lens and 2 x Inon D-2000 flashes.

for more information about this species go to one of the links below
OPK - Opistobranquis Encyclopedia of Marine Life of Britain and Ireland sea slug forum